diff --git a/api/client_test.go b/api/client_test.go
index 874387868..5be652574 100644
--- a/api/client_test.go
+++ b/api/client_test.go
@@ -21,13 +21,13 @@ import (
 	"net/http/httptest"
 	"net/url"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestConfig(t *testing.T) {
 	c := Config{}
-	if c.roundTripper() != DefaultRoundTripper {
-		t.Fatalf("expected default roundtripper for nil RoundTripper field")
-	}
+	require.Equalf(t, c.roundTripper(), DefaultRoundTripper, "expected default roundtripper for nil RoundTripper field")
 }
 
 func TestClientURL(t *testing.T) {
@@ -99,9 +99,7 @@ func TestClientURL(t *testing.T) {
 
 	for _, test := range tests {
 		ep, err := url.Parse(test.address)
-		if err != nil {
-			t.Fatal(err)
-		}
+		require.NoError(t, err)
 
 		hclient := &httpClient{
 			endpoint: ep,
@@ -140,22 +138,16 @@ func BenchmarkClient(b *testing.B) {
 			client, err := NewClient(Config{
 				Address: testServer.URL,
 			})
-			if err != nil {
-				b.Fatalf("Failed to initialize client: %v", err)
-			}
+			require.NoErrorf(b, err, "Failed to initialize client: %v", err)
 			url, err := url.Parse(testServer.URL + "/prometheus/api/v1/query?query=up")
-			if err != nil {
-				b.Fatalf("Failed to parse url: %v", err)
-			}
+			require.NoErrorf(b, err, "Failed to parse url: %v", err)
 			req := &http.Request{
 				URL: url,
 			}
 			b.ResetTimer()
 			for i := 0; i < b.N; i++ {
 				_, _, err := client.Do(ctx, req)
-				if err != nil {
-					b.Fatalf("Query failed: %v", err)
-				}
+				require.NoErrorf(b, err, "Query failed: %v", err)
 			}
 			b.StopTimer()
 		})
diff --git a/api/prometheus/v1/api.go b/api/prometheus/v1/api.go
index cddf027fd..8fd795a97 100644
--- a/api/prometheus/v1/api.go
+++ b/api/prometheus/v1/api.go
@@ -28,7 +28,6 @@ import (
 	"unsafe"
 
 	json "github.com/json-iterator/go"
-
 	"github.com/prometheus/common/model"
 
 	"github.com/prometheus/client_golang/api"
diff --git a/api/prometheus/v1/api_bench_test.go b/api/prometheus/v1/api_bench_test.go
index f1f8000ef..e216dee22 100644
--- a/api/prometheus/v1/api_bench_test.go
+++ b/api/prometheus/v1/api_bench_test.go
@@ -19,8 +19,8 @@ import (
 	"time"
 
 	jsoniter "github.com/json-iterator/go"
-
 	"github.com/prometheus/common/model"
+	"github.com/stretchr/testify/require"
 )
 
 func generateData(timeseries, datapoints int) (floatMatrix, histogramMatrix model.Matrix) {
@@ -111,45 +111,37 @@ func BenchmarkSamplesJsonSerialization(b *testing.B) {
 					floats, histograms := generateData(timeseriesCount, datapointCount)
 
 					floatBytes, err := json.Marshal(floats)
-					if err != nil {
-						b.Fatalf("Error marshaling: %v", err)
-					}
+					require.NoErrorf(b, err, "Error marshaling: %v", err)
 					histogramBytes, err := json.Marshal(histograms)
-					if err != nil {
-						b.Fatalf("Error marshaling: %v", err)
-					}
+					require.NoErrorf(b, err, "Error marshaling: %v", err)
 
 					b.Run("marshal", func(b *testing.B) {
 						b.Run("encoding/json/floats", func(b *testing.B) {
 							b.ReportAllocs()
 							for i := 0; i < b.N; i++ {
-								if _, err := json.Marshal(floats); err != nil {
-									b.Fatal(err)
-								}
+								_, err := json.Marshal(floats)
+								require.NoError(b, err)
 							}
 						})
 						b.Run("jsoniter/floats", func(b *testing.B) {
 							b.ReportAllocs()
 							for i := 0; i < b.N; i++ {
-								if _, err := jsoniter.Marshal(floats); err != nil {
-									b.Fatal(err)
-								}
+								_, err := jsoniter.Marshal(floats)
+								require.NoError(b, err)
 							}
 						})
 						b.Run("encoding/json/histograms", func(b *testing.B) {
 							b.ReportAllocs()
 							for i := 0; i < b.N; i++ {
-								if _, err := json.Marshal(histograms); err != nil {
-									b.Fatal(err)
-								}
+								_, err := json.Marshal(histograms)
+								require.NoError(b, err)
 							}
 						})
 						b.Run("jsoniter/histograms", func(b *testing.B) {
 							b.ReportAllocs()
 							for i := 0; i < b.N; i++ {
-								if _, err := jsoniter.Marshal(histograms); err != nil {
-									b.Fatal(err)
-								}
+								_, err := jsoniter.Marshal(histograms)
+								require.NoError(b, err)
 							}
 						})
 					})
@@ -159,36 +151,28 @@ func BenchmarkSamplesJsonSerialization(b *testing.B) {
 							b.ReportAllocs()
 							var m model.Matrix
 							for i := 0; i < b.N; i++ {
-								if err := json.Unmarshal(floatBytes, &m); err != nil {
-									b.Fatal(err)
-								}
+								require.NoError(b, json.Unmarshal(floatBytes, &m))
 							}
 						})
 						b.Run("jsoniter/floats", func(b *testing.B) {
 							b.ReportAllocs()
 							var m model.Matrix
 							for i := 0; i < b.N; i++ {
-								if err := jsoniter.Unmarshal(floatBytes, &m); err != nil {
-									b.Fatal(err)
-								}
+								require.NoError(b, jsoniter.Unmarshal(floatBytes, &m))
 							}
 						})
 						b.Run("encoding/json/histograms", func(b *testing.B) {
 							b.ReportAllocs()
 							var m model.Matrix
 							for i := 0; i < b.N; i++ {
-								if err := json.Unmarshal(histogramBytes, &m); err != nil {
-									b.Fatal(err)
-								}
+								require.NoError(b, json.Unmarshal(histogramBytes, &m))
 							}
 						})
 						b.Run("jsoniter/histograms", func(b *testing.B) {
 							b.ReportAllocs()
 							var m model.Matrix
 							for i := 0; i < b.N; i++ {
-								if err := jsoniter.Unmarshal(histogramBytes, &m); err != nil {
-									b.Fatal(err)
-								}
+								require.NoError(b, jsoniter.Unmarshal(histogramBytes, &m))
 							}
 						})
 					})
diff --git a/api/prometheus/v1/api_test.go b/api/prometheus/v1/api_test.go
index 01ddf45ca..46f0688b4 100644
--- a/api/prometheus/v1/api_test.go
+++ b/api/prometheus/v1/api_test.go
@@ -28,8 +28,8 @@ import (
 	"time"
 
 	json "github.com/json-iterator/go"
-
 	"github.com/prometheus/common/model"
+	"github.com/stretchr/testify/require"
 )
 
 type apiTest struct {
@@ -73,9 +73,7 @@ func (c *apiTestClient) Do(_ context.Context, req *http.Request) (*http.Response
 	}
 
 	b, err := json.Marshal(test.inRes)
-	if err != nil {
-		c.Fatal(err)
-	}
+	require.NoError(c, err)
 
 	resp := &http.Response{}
 	if test.inStatusCode != 0 {
@@ -1222,9 +1220,7 @@ func TestAPIs(t *testing.T) {
 			}
 
 			if test.err != nil {
-				if err == nil {
-					t.Fatalf("expected error %q but got none", test.err)
-				}
+				require.Errorf(t, err, "expected error %q but got none", test.err)
 				if err.Error() != test.err.Error() {
 					t.Errorf("unexpected error: want %s, got %s", test.err, err)
 				}
@@ -1237,9 +1233,7 @@ func TestAPIs(t *testing.T) {
 				}
 				return
 			}
-			if err != nil {
-				t.Fatalf("unexpected error: %s", err)
-			}
+			require.NoErrorf(t, err, "unexpected error: %s", err)
 
 			if !reflect.DeepEqual(res, test.res) {
 				t.Errorf("unexpected result: want %v, got %v", test.res, res)
@@ -1268,12 +1262,8 @@ func (c *testClient) URL(ep string, args map[string]string) *url.URL {
 }
 
 func (c *testClient) Do(ctx context.Context, req *http.Request) (*http.Response, []byte, error) {
-	if ctx == nil {
-		c.Fatalf("context was not passed down")
-	}
-	if req != c.req {
-		c.Fatalf("request was not passed down")
-	}
+	require.NotNilf(c, ctx, "context was not passed down")
+	require.Samef(c, req, c.req, "request was not passed down")
 
 	test := <-c.ch
 
@@ -1285,9 +1275,7 @@ func (c *testClient) Do(ctx context.Context, req *http.Request) (*http.Response,
 		b = []byte(v)
 	default:
 		b, err = json.Marshal(v)
-		if err != nil {
-			c.Fatal(err)
-		}
+		require.NoError(c, err)
 	}
 
 	resp := &http.Response{
@@ -1436,30 +1424,20 @@ func TestAPIClientDo(t *testing.T) {
 			_, body, warnings, err := client.Do(context.Background(), tc.req)
 
 			if test.expectedWarnings != nil {
-				if !reflect.DeepEqual(test.expectedWarnings, warnings) {
-					t.Fatalf("mismatch in warnings expected=%v actual=%v", test.expectedWarnings, warnings)
-				}
+				require.Truef(t, reflect.DeepEqual(test.expectedWarnings, warnings), "mismatch in warnings expected=%v actual=%v", test.expectedWarnings, warnings)
 			} else {
-				if warnings != nil {
-					t.Fatalf("unexpected warnings: %v", warnings)
-				}
+				require.Nilf(t, warnings, "unexpected warnings: %v", warnings)
 			}
 
 			if test.expectedErr != nil {
-				if err == nil {
-					t.Fatal("expected error, but got none")
-				}
+				require.Errorf(t, err, "expected error, but got none")
 
-				if test.expectedErr.Error() != err.Error() {
-					t.Fatalf("expected error:%v, but got:%v", test.expectedErr.Error(), err.Error())
-				}
+				require.Equalf(t, test.expectedErr.Error(), err.Error(), "expected error:%v, but got:%v", test.expectedErr.Error(), err.Error())
 
 				if test.expectedErr.Detail != "" {
 					apiErr := &Error{}
 					if errors.As(err, &apiErr) {
-						if apiErr.Detail != test.expectedErr.Detail {
-							t.Fatalf("expected error detail :%v, but got:%v", apiErr.Detail, test.expectedErr.Detail)
-						}
+						require.Equalf(t, apiErr.Detail, test.expectedErr.Detail, "expected error detail :%v, but got:%v", apiErr.Detail, test.expectedErr.Detail)
 					} else {
 						t.Fatalf("expected v1.Error instance, but got:%T", err)
 					}
@@ -1468,12 +1446,8 @@ func TestAPIClientDo(t *testing.T) {
 				return
 			}
 
-			if err != nil {
-				t.Fatalf("unexpected error:%v", err)
-			}
-			if test.expectedBody != string(body) {
-				t.Fatalf("expected body :%v, but got:%v", test.expectedBody, string(body))
-			}
+			require.NoErrorf(t, err, "unexpected error:%v", err)
+			require.Equalf(t, test.expectedBody, string(body), "expected body :%v, but got:%v", test.expectedBody, string(body))
 		})
 	}
 }
@@ -1548,28 +1522,18 @@ func TestSamplesJSONSerialization(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.expected, func(t *testing.T) {
 			b, err := json.Marshal(test.point)
-			if err != nil {
-				t.Fatal(err)
-			}
-			if string(b) != test.expected {
-				t.Fatalf("Mismatch marshal expected=%s actual=%s", test.expected, string(b))
-			}
+			require.NoError(t, err)
+			require.Equalf(t, test.expected, string(b), "Mismatch marshal expected=%s actual=%s", test.expected, string(b))
 
 			// To test Unmarshal we will Unmarshal then re-Marshal this way we
 			// can do a string compare, otherwise Nan values don't show equivalence
 			// properly.
 			var sp model.SamplePair
-			if err = json.Unmarshal(b, &sp); err != nil {
-				t.Fatal(err)
-			}
+			require.NoError(t, json.Unmarshal(b, &sp))
 
 			b, err = json.Marshal(sp)
-			if err != nil {
-				t.Fatal(err)
-			}
-			if string(b) != test.expected {
-				t.Fatalf("Mismatch marshal expected=%s actual=%s", test.expected, string(b))
-			}
+			require.NoError(t, err)
+			require.Equalf(t, test.expected, string(b), "Mismatch marshal expected=%s actual=%s", test.expected, string(b))
 		})
 	}
 }
@@ -1653,28 +1617,18 @@ func TestHistogramJSONSerialization(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			b, err := json.Marshal(test.point)
-			if err != nil {
-				t.Fatal(err)
-			}
-			if string(b) != test.expected {
-				t.Fatalf("Mismatch marshal expected=%s actual=%s", test.expected, string(b))
-			}
+			require.NoError(t, err)
+			require.Equalf(t, test.expected, string(b), "Mismatch marshal expected=%s actual=%s", test.expected, string(b))
 
 			// To test Unmarshal we will Unmarshal then re-Marshal. This way we
 			// can do a string compare, otherwise NaN values don't show equivalence
 			// properly.
 			var sp model.SampleHistogramPair
-			if err = json.Unmarshal(b, &sp); err != nil {
-				t.Fatal(err)
-			}
+			require.NoError(t, json.Unmarshal(b, &sp))
 
 			b, err = json.Marshal(sp)
-			if err != nil {
-				t.Fatal(err)
-			}
-			if string(b) != test.expected {
-				t.Fatalf("Mismatch marshal expected=%s actual=%s", test.expected, string(b))
-			}
+			require.NoError(t, err)
+			require.Equalf(t, test.expected, string(b), "Mismatch marshal expected=%s actual=%s", test.expected, string(b))
 		})
 	}
 }
@@ -1711,21 +1665,14 @@ func TestSampleStreamJSONSerialization(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			b, err := json.Marshal(test.stream)
-			if err != nil {
-				t.Fatal(err)
-			}
-			if string(b) != test.expectedJSON {
-				t.Fatalf("Mismatch marshal expected=%s actual=%s", test.expectedJSON, string(b))
-			}
+			require.NoError(t, err)
+			require.Equalf(t, test.expectedJSON, string(b), "Mismatch marshal expected=%s actual=%s", test.expectedJSON, string(b))
 
 			var stream model.SampleStream
-			if err = json.Unmarshal(b, &stream); err != nil {
-				t.Fatal(err)
-			}
+			err = json.Unmarshal(b, &stream)
+			require.NoError(t, err)
 
-			if !reflect.DeepEqual(test.stream, stream) {
-				t.Fatalf("Mismatch after unmarshal expected=%#v actual=%#v", test.stream, stream)
-			}
+			require.Truef(t, reflect.DeepEqual(test.stream, stream), "Mismatch after unmarshal expected=%#v actual=%#v", test.stream, stream)
 		})
 	}
 }
@@ -1806,9 +1753,7 @@ func TestDoGetFallback(t *testing.T) {
 	defer server.Close()
 
 	u, err := url.Parse(server.URL)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	client := &httpTestClient{client: *(server.Client())}
 	api := &apiClientImpl{
 		client: client,
@@ -1816,49 +1761,28 @@ func TestDoGetFallback(t *testing.T) {
 
 	// Do a post, and ensure that the post succeeds.
 	_, b, _, err := api.DoGetFallback(context.TODO(), u, v)
-	if err != nil {
-		t.Fatalf("Error doing local request: %v", err)
-	}
+	require.NoErrorf(t, err, "Error doing local request: %v", err)
 	resp := &testResponse{}
-	if err := json.Unmarshal(b, resp); err != nil {
-		t.Fatal(err)
-	}
-	if resp.Method != http.MethodPost {
-		t.Fatalf("Mismatch method")
-	}
-	if resp.Values != v.Encode() {
-		t.Fatalf("Mismatch in values")
-	}
+	err = json.Unmarshal(b, resp)
+	require.NoError(t, err)
+	require.Equalf(t, http.MethodPost, resp.Method, "Mismatch method")
+	require.Equalf(t, resp.Values, v.Encode(), "Mismatch in values")
 
 	// Do a fallback to a get on 405.
 	u.Path = "/blockPost405"
 	_, b, _, err = api.DoGetFallback(context.TODO(), u, v)
-	if err != nil {
-		t.Fatalf("Error doing local request: %v", err)
-	}
-	if err := json.Unmarshal(b, resp); err != nil {
-		t.Fatal(err)
-	}
-	if resp.Method != http.MethodGet {
-		t.Fatalf("Mismatch method")
-	}
-	if resp.Values != v.Encode() {
-		t.Fatalf("Mismatch in values")
-	}
+	require.NoErrorf(t, err, "Error doing local request: %v", err)
+	err = json.Unmarshal(b, resp)
+	require.NoError(t, err)
+	require.Equalf(t, http.MethodGet, resp.Method, "Mismatch method")
+	require.Equalf(t, resp.Values, v.Encode(), "Mismatch in values")
 
 	// Do a fallback to a get on 501.
 	u.Path = "/blockPost501"
 	_, b, _, err = api.DoGetFallback(context.TODO(), u, v)
-	if err != nil {
-		t.Fatalf("Error doing local request: %v", err)
-	}
-	if err := json.Unmarshal(b, resp); err != nil {
-		t.Fatal(err)
-	}
-	if resp.Method != http.MethodGet {
-		t.Fatalf("Mismatch method")
-	}
-	if resp.Values != v.Encode() {
-		t.Fatalf("Mismatch in values")
-	}
+	require.NoErrorf(t, err, "Error doing local request: %v", err)
+	err = json.Unmarshal(b, resp)
+	require.NoError(t, err)
+	require.Equalf(t, http.MethodGet, resp.Method, "Mismatch method")
+	require.Equalf(t, resp.Values, v.Encode(), "Mismatch in values")
 }
diff --git a/examples/simple/main.go b/examples/simple/main.go
index 935f80577..00059924f 100644
--- a/examples/simple/main.go
+++ b/examples/simple/main.go
@@ -19,9 +19,8 @@ import (
 	"log"
 	"net/http"
 
-	"github.com/prometheus/client_golang/prometheus/collectors"
-
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
diff --git a/go.mod b/go.mod
index 1a0348a66..f89356a6e 100644
--- a/go.mod
+++ b/go.mod
@@ -12,21 +12,25 @@ require (
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/common v0.60.1
 	github.com/prometheus/procfs v0.15.1
+	github.com/stretchr/testify v1.9.0
 	golang.org/x/sys v0.26.0
 	google.golang.org/protobuf v1.35.1
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/jpillora/backoff v1.0.0 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/net v0.29.0 // indirect
 	golang.org/x/oauth2 v0.23.0 // indirect
 	golang.org/x/text v0.18.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
 
 exclude github.com/prometheus/client_golang v1.12.1
diff --git a/prometheus/collectors/dbstats_collector_test.go b/prometheus/collectors/dbstats_collector_test.go
index 057e24384..60ccd888d 100644
--- a/prometheus/collectors/dbstats_collector_test.go
+++ b/prometheus/collectors/dbstats_collector_test.go
@@ -17,6 +17,8 @@ import (
 	"database/sql"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/prometheus/client_golang/prometheus"
 )
 
@@ -24,21 +26,17 @@ func TestDBStatsCollector(t *testing.T) {
 	reg := prometheus.NewPedanticRegistry()
 	{
 		db := new(sql.DB)
-		if err := reg.Register(NewDBStatsCollector(db, "db_A")); err != nil {
-			t.Fatal(err)
-		}
+		err := reg.Register(NewDBStatsCollector(db, "db_A"))
+		require.NoError(t, err)
 	}
 	{
 		db := new(sql.DB)
-		if err := reg.Register(NewDBStatsCollector(db, "db_B")); err != nil {
-			t.Fatal(err)
-		}
+		err := reg.Register(NewDBStatsCollector(db, "db_B"))
+		require.NoError(t, err)
 	}
 
 	mfs, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	names := []string{
 		"go_sql_max_open_connections",
diff --git a/prometheus/collectors/gen_go_collector_set.go b/prometheus/collectors/gen_go_collector_set.go
index 7a5044fa7..434d6bf62 100644
--- a/prometheus/collectors/gen_go_collector_set.go
+++ b/prometheus/collectors/gen_go_collector_set.go
@@ -29,10 +29,10 @@ import (
 	"strings"
 	"text/template"
 
+	version "github.com/hashicorp/go-version"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/internal"
-
-	version "github.com/hashicorp/go-version"
 )
 
 type metricGroup struct {
diff --git a/prometheus/collectors/go_collector_latest_test.go b/prometheus/collectors/go_collector_latest_test.go
index 974db6c13..1ee062d9a 100644
--- a/prometheus/collectors/go_collector_latest_test.go
+++ b/prometheus/collectors/go_collector_latest_test.go
@@ -25,6 +25,7 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -87,9 +88,7 @@ func TestGoCollectorMarshalling(t *testing.T) {
 		}),
 	))
 	result, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	if _, err := json.Marshal(result); err != nil {
 		t.Errorf("json marshalling should not fail, %v", err)
@@ -100,9 +99,7 @@ func TestWithGoCollectorDefault(t *testing.T) {
 	reg := prometheus.NewPedanticRegistry()
 	reg.MustRegister(NewGoCollector())
 	result, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	got := []string{}
 	for _, r := range result {
@@ -122,9 +119,7 @@ func TestWithGoCollectorMemStatsMetricsDisabled(t *testing.T) {
 		WithGoCollectorMemStatsMetricsDisabled(),
 	))
 	result, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	got := []string{}
 	for _, r := range result {
@@ -180,10 +175,7 @@ func TestGoCollectorAllowList(t *testing.T) {
 				WithGoCollectorRuntimeMetrics(test.rules...),
 			))
 			result, err := reg.Gather()
-			if err != nil {
-				t.Fatal(err)
-			}
-
+			require.NoError(t, err)
 			got := []string{}
 			for _, r := range result {
 				got = append(got, r.GetName())
@@ -242,9 +234,7 @@ func TestGoCollectorDenyList(t *testing.T) {
 				WithoutGoCollectorRuntimeMetrics(test.matchers...),
 			))
 			result, err := reg.Gather()
-			if err != nil {
-				t.Fatal(err)
-			}
+			require.NoError(t, err)
 
 			got := []string{}
 			for _, r := range result {
diff --git a/prometheus/counter_test.go b/prometheus/counter_test.go
index 3686199b5..7777eba96 100644
--- a/prometheus/counter_test.go
+++ b/prometheus/counter_test.go
@@ -21,6 +21,7 @@ import (
 	"time"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
@@ -269,9 +270,7 @@ func TestCounterExemplar(t *testing.T) {
 	}).(*counter)
 
 	ts := timestamppb.New(now)
-	if err := ts.CheckValid(); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, ts.CheckValid())
 	expectedExemplar := &dto.Exemplar{
 		Label: []*dto.LabelPair{
 			{Name: proto.String("foo"), Value: proto.String("bar")},
@@ -361,13 +360,10 @@ func expectCTsForMetricVecValues(t testing.TB, vec *MetricVec, typ dto.MetricTyp
 	for val, ct := range ctsPerLabelValue {
 		var metric dto.Metric
 		m, err := vec.GetMetricWithLabelValues(val)
-		if err != nil {
-			t.Fatal(err)
-		}
+		require.NoError(t, err)
 
-		if err := m.Write(&metric); err != nil {
-			t.Fatal(err)
-		}
+		err = m.Write(&metric)
+		require.NoError(t, err)
 
 		var gotTs time.Time
 		switch typ {
diff --git a/prometheus/example_metricvec_test.go b/prometheus/example_metricvec_test.go
index 59e43f8f8..30ab00452 100644
--- a/prometheus/example_metricvec_test.go
+++ b/prometheus/example_metricvec_test.go
@@ -16,9 +16,8 @@ package prometheus_test
 import (
 	"fmt"
 
-	"google.golang.org/protobuf/proto"
-
 	dto "github.com/prometheus/client_model/go"
+	"google.golang.org/protobuf/proto"
 
 	"github.com/prometheus/client_golang/prometheus"
 )
diff --git a/prometheus/gauge_test.go b/prometheus/gauge_test.go
index 26759fbbc..9f193ff3d 100644
--- a/prometheus/gauge_test.go
+++ b/prometheus/gauge_test.go
@@ -22,6 +22,7 @@ import (
 	"time"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -91,9 +92,8 @@ func TestGaugeConcurrency(t *testing.T) {
 		return true
 	}
 
-	if err := quick.Check(it, nil); err != nil {
-		t.Fatal(err)
-	}
+	err := quick.Check(it, nil)
+	require.NoError(t, err)
 }
 
 func TestGaugeVecConcurrency(t *testing.T) {
@@ -156,9 +156,8 @@ func TestGaugeVecConcurrency(t *testing.T) {
 		return true
 	}
 
-	if err := quick.Check(it, nil); err != nil {
-		t.Fatal(err)
-	}
+	err := quick.Check(it, nil)
+	require.NoError(t, err)
 }
 
 func TestGaugeFunc(t *testing.T) {
diff --git a/prometheus/gen_go_collector_metrics_set.go b/prometheus/gen_go_collector_metrics_set.go
index f1db3d8d1..22b3ec9ed 100644
--- a/prometheus/gen_go_collector_metrics_set.go
+++ b/prometheus/gen_go_collector_metrics_set.go
@@ -28,10 +28,10 @@ import (
 	"strings"
 	"text/template"
 
+	version "github.com/hashicorp/go-version"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/internal"
-
-	version "github.com/hashicorp/go-version"
 )
 
 func main() {
diff --git a/prometheus/go_collector_latest.go b/prometheus/go_collector_latest.go
index 6b8684731..363bd7309 100644
--- a/prometheus/go_collector_latest.go
+++ b/prometheus/go_collector_latest.go
@@ -24,10 +24,10 @@ import (
 	"strings"
 	"sync"
 
-	"github.com/prometheus/client_golang/prometheus/internal"
-
 	dto "github.com/prometheus/client_model/go"
 	"google.golang.org/protobuf/proto"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
 )
 
 const (
diff --git a/prometheus/go_collector_latest_test.go b/prometheus/go_collector_latest_test.go
index 2fbe01bae..9e800551a 100644
--- a/prometheus/go_collector_latest_test.go
+++ b/prometheus/go_collector_latest_test.go
@@ -26,6 +26,7 @@ import (
 	"testing"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/client_golang/prometheus/internal"
 )
@@ -162,13 +163,9 @@ func TestBatchHistogram(t *testing.T) {
 			break
 		}
 	}
-	if mhist == nil {
-		t.Fatal("failed to find metric to test")
-	}
+	require.NotNilf(t, mhist, "failed to find metric to test")
 	hist, ok := mhist.(*batchHistogram)
-	if !ok {
-		t.Fatal("found metric is not a runtime/metrics histogram")
-	}
+	require.Truef(t, ok, "found metric is not a runtime/metrics histogram")
 
 	// Make a bunch of allocations then do another collection.
 	//
diff --git a/prometheus/graphite/bridge.go b/prometheus/graphite/bridge.go
index 84eac0de9..821ef436e 100644
--- a/prometheus/graphite/bridge.go
+++ b/prometheus/graphite/bridge.go
@@ -25,11 +25,10 @@ import (
 	"sort"
 	"time"
 
+	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
 	"github.com/prometheus/common/model"
 
-	dto "github.com/prometheus/client_model/go"
-
 	"github.com/prometheus/client_golang/prometheus"
 )
 
diff --git a/prometheus/graphite/bridge_test.go b/prometheus/graphite/bridge_test.go
index 8c596d5ac..67d2f6c5f 100644
--- a/prometheus/graphite/bridge_test.go
+++ b/prometheus/graphite/bridge_test.go
@@ -31,6 +31,7 @@ import (
 	"time"
 
 	"github.com/prometheus/common/model"
+	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/client_golang/prometheus"
 )
@@ -390,12 +391,8 @@ func TestPush(t *testing.T) {
 	case got := <-nmg.readc:
 		for _, want := range wants {
 			matched, err := regexp.MatchString(want, got)
-			if err != nil {
-				t.Fatalf("error pushing: %v", err)
-			}
-			if !matched {
-				t.Fatalf("missing metric:\nno match for %s received by server:\n%s", want, got)
-			}
+			require.NoErrorf(t, err, "error pushing: %v", err)
+			require.Truef(t, matched, "missing metric:\nno match for %s received by server:\n%s", want, got)
 		}
 		return
 	case err := <-nmg.errc:
diff --git a/prometheus/histogram.go b/prometheus/histogram.go
index 08bef3d87..4cc4c1ddf 100644
--- a/prometheus/histogram.go
+++ b/prometheus/histogram.go
@@ -23,7 +23,6 @@ import (
 	"time"
 
 	dto "github.com/prometheus/client_model/go"
-
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
diff --git a/prometheus/histogram_test.go b/prometheus/histogram_test.go
index c2a14ae72..a17dabf0d 100644
--- a/prometheus/histogram_test.go
+++ b/prometheus/histogram_test.go
@@ -25,11 +25,12 @@ import (
 	"testing/quick"
 	"time"
 
-	"github.com/prometheus/client_golang/prometheus/internal"
-
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
 )
 
 func benchmarkHistogramObserve(w int, b *testing.B) {
@@ -392,9 +393,7 @@ func TestHistogramAtomicObserve(t *testing.T) {
 
 	for i := 0; i < 100; i++ {
 		m := &dto.Metric{}
-		if err := his.Write(m); err != nil {
-			t.Fatal("unexpected error writing histogram:", err)
-		}
+		require.NoErrorf(t, his.Write(m), "unexpected error writing histogram")
 		h := m.GetHistogram()
 		if h.GetSampleCount() != uint64(h.GetSampleSum()) ||
 			h.GetSampleCount() != h.GetBucket()[1].GetCumulativeCount() ||
@@ -420,9 +419,7 @@ func TestHistogramExemplar(t *testing.T) {
 	}).(*histogram)
 
 	ts := timestamppb.New(now)
-	if err := ts.CheckValid(); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, ts.CheckValid())
 	expectedExemplars := []*dto.Exemplar{
 		nil,
 		{
@@ -994,13 +991,9 @@ func TestNativeHistogram(t *testing.T) {
 				}
 			}
 			m := &dto.Metric{}
-			if err := his.Write(m); err != nil {
-				t.Fatal("unexpected error writing metric", err)
-			}
+			require.NoErrorf(t, his.Write(m), "unexpected error writing metric")
 			got := m.Histogram
-			if !proto.Equal(s.want, got) {
-				t.Errorf("want histogram %q, got %q", s.want, got)
-			}
+			require.Truef(t, proto.Equal(s.want, got), "want histogram %q, got %q", s.want, got)
 		})
 	}
 }
@@ -1081,17 +1074,13 @@ func TestNativeHistogramConcurrency(t *testing.T) {
 		current := 0
 		for _, delta := range m.Histogram.GetNegativeDelta() {
 			current += int(delta)
-			if current < 0 {
-				t.Fatalf("negative bucket population negative: %d", current)
-			}
+			require.GreaterOrEqualf(t, current, 0, "negative bucket population negative: %d", current)
 			sumBuckets += current
 		}
 		current = 0
 		for _, delta := range m.Histogram.GetPositiveDelta() {
 			current += int(delta)
-			if current < 0 {
-				t.Fatalf("positive bucket population negative: %d", current)
-			}
+			require.GreaterOrEqualf(t, current, 0, "positive bucket population negative: %d", current)
 			sumBuckets += current
 		}
 		if got, want := sumBuckets, int(*m.Histogram.SampleCount); got != want {
@@ -1208,9 +1197,7 @@ func TestHistogramCreatedTimestamp(t *testing.T) {
 	})
 
 	var metric dto.Metric
-	if err := histogram.Write(&metric); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, histogram.Write(&metric))
 
 	if metric.Histogram.CreatedTimestamp.AsTime().Unix() != now.Unix() {
 		t.Errorf("expected created timestamp %d, got %d", now.Unix(), metric.Histogram.CreatedTimestamp.AsTime().Unix())
@@ -1229,9 +1216,7 @@ func TestHistogramVecCreatedTimestamp(t *testing.T) {
 	histogram := histogramVec.WithLabelValues("value").(Histogram)
 
 	var metric dto.Metric
-	if err := histogram.Write(&metric); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, histogram.Write(&metric))
 
 	if metric.Histogram.CreatedTimestamp.AsTime().Unix() != now.Unix() {
 		t.Errorf("expected created timestamp %d, got %d", now.Unix(), metric.Histogram.CreatedTimestamp.AsTime().Unix())
@@ -1287,14 +1272,10 @@ func TestNewConstHistogramWithCreatedTimestamp(t *testing.T) {
 	createdTs := time.Unix(1719670764, 123)
 
 	h, err := NewConstHistogramWithCreatedTimestamp(metricDesc, 100, 200, buckets, createdTs)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	var metric dto.Metric
-	if err := h.Write(&metric); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, h.Write(&metric))
 
 	if metric.Histogram.CreatedTimestamp.AsTime().UnixMicro() != createdTs.UnixMicro() {
 		t.Errorf("Expected created timestamp %v, got %v", createdTs, &metric.Histogram.CreatedTimestamp)
diff --git a/prometheus/metric_test.go b/prometheus/metric_test.go
index 629aa4f84..4c72253bc 100644
--- a/prometheus/metric_test.go
+++ b/prometheus/metric_test.go
@@ -18,7 +18,7 @@ import (
 	"testing"
 
 	dto "github.com/prometheus/client_model/go"
-
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -62,9 +62,7 @@ func TestWithExemplarsMetric(t *testing.T) {
 			{Value: proto.Float64(25.1)},
 		}}
 		metric := dto.Metric{}
-		if err := m.Write(&metric); err != nil {
-			t.Fatal(err)
-		}
+		require.NoError(t, m.Write(&metric))
 		if want, got := 5, len(metric.GetHistogram().Bucket); want != got {
 			t.Errorf("want %v, got %v", want, got)
 		}
diff --git a/prometheus/process_collector_test.go b/prometheus/process_collector_test.go
index 9bead32a9..50543bdee 100644
--- a/prometheus/process_collector_test.go
+++ b/prometheus/process_collector_test.go
@@ -26,10 +26,10 @@ import (
 	"strings"
 	"testing"
 
+	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
 	"github.com/prometheus/procfs"
-
-	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 )
 
 func TestProcessCollector(t *testing.T) {
@@ -38,27 +38,20 @@ func TestProcessCollector(t *testing.T) {
 	}
 
 	registry := NewPedanticRegistry()
-	if err := registry.Register(NewProcessCollector(ProcessCollectorOpts{})); err != nil {
-		t.Fatal(err)
-	}
-	if err := registry.Register(NewProcessCollector(ProcessCollectorOpts{
+	require.NoError(t, registry.Register(NewProcessCollector(ProcessCollectorOpts{})))
+	require.NoError(t, registry.Register(NewProcessCollector(ProcessCollectorOpts{
 		PidFn:        func() (int, error) { return os.Getpid(), nil },
 		Namespace:    "foobar",
 		ReportErrors: true, // No errors expected, just to see if none are reported.
-	})); err != nil {
-		t.Fatal(err)
-	}
+	})))
 
 	mfs, err := registry.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	var buf bytes.Buffer
 	for _, mf := range mfs {
-		if _, err := expfmt.MetricFamilyToText(&buf, mf); err != nil {
-			t.Fatal(err)
-		}
+		_, err := expfmt.MetricFamilyToText(&buf, mf)
+		require.NoError(t, err)
 	}
 
 	for _, re := range []*regexp.Regexp{
diff --git a/prometheus/process_collector_windows_test.go b/prometheus/process_collector_windows_test.go
index 670c0fc53..8d9b85446 100644
--- a/prometheus/process_collector_windows_test.go
+++ b/prometheus/process_collector_windows_test.go
@@ -20,31 +20,27 @@ import (
 	"testing"
 
 	"github.com/prometheus/common/expfmt"
+	"github.com/stretchr/testify/require"
 )
 
 func TestWindowsProcessCollector(t *testing.T) {
 	registry := NewRegistry()
-	if err := registry.Register(NewProcessCollector(ProcessCollectorOpts{})); err != nil {
-		t.Fatal(err)
-	}
-	if err := registry.Register(NewProcessCollector(ProcessCollectorOpts{
+	err := registry.Register(NewProcessCollector(ProcessCollectorOpts{}))
+	require.False(t, err != nil)
+	err = registry.Register(NewProcessCollector(ProcessCollectorOpts{
 		PidFn:        func() (int, error) { return os.Getpid(), nil },
 		Namespace:    "foobar",
 		ReportErrors: true, // No errors expected, just to see if none are reported.
-	})); err != nil {
-		t.Fatal(err)
-	}
+	}))
+	require.False(t, err != nil)
 
 	mfs, err := registry.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.False(t, err != nil)
 
 	var buf bytes.Buffer
 	for _, mf := range mfs {
-		if _, err := expfmt.MetricFamilyToText(&buf, mf); err != nil {
-			t.Fatal(err)
-		}
+		_, err := expfmt.MetricFamilyToText(&buf, mf)
+		require.False(t, err != nil)
 	}
 
 	for _, re := range []*regexp.Regexp{
diff --git a/prometheus/promhttp/instrument_client_test.go b/prometheus/promhttp/instrument_client_test.go
index ce7c4da54..340158142 100644
--- a/prometheus/promhttp/instrument_client_test.go
+++ b/prometheus/promhttp/instrument_client_test.go
@@ -24,11 +24,12 @@ import (
 	"testing"
 	"time"
 
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/testutil"
-
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/testutil"
 )
 
 func makeInstrumentedClient(opts ...Option) (*http.Client, *prometheus.Registry) {
@@ -124,12 +125,9 @@ func assetMetricAndExemplars(
 	t.Helper()
 
 	mfs, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
-	if want, got := expectedNumMetrics, len(mfs); want != got {
-		t.Fatalf("unexpected number of metric families gathered, want %d, got %d", want, got)
-	}
+	require.NoError(t, err)
+	want, got := expectedNumMetrics, len(mfs)
+	require.Equalf(t, want, got, "unexpected number of metric families gathered, want %d, got %d", want, got)
 
 	for _, mf := range mfs {
 		if len(mf.Metric) == 0 {
@@ -190,9 +188,7 @@ func TestClientMiddlewareAPI(t *testing.T) {
 	defer backend.Close()
 
 	resp, err := client.Get(backend.URL)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	defer resp.Body.Close()
 
 	assetMetricAndExemplars(t, reg, 3, nil)
@@ -208,9 +204,7 @@ func TestClientMiddlewareAPI_WithExemplars(t *testing.T) {
 	defer backend.Close()
 
 	resp, err := client.Get(backend.URL)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	defer resp.Body.Close()
 
 	assetMetricAndExemplars(t, reg, 3, labelsToLabelPair(exemplar))
@@ -224,9 +218,7 @@ func TestClientMiddlewareAPI_WithRequestContext(t *testing.T) {
 	defer backend.Close()
 
 	req, err := http.NewRequest("GET", backend.URL, nil)
-	if err != nil {
-		t.Fatalf("%v", err)
-	}
+	require.NoError(t, err)
 
 	// Set a context with a long timeout.
 	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
@@ -234,18 +226,13 @@ func TestClientMiddlewareAPI_WithRequestContext(t *testing.T) {
 	req = req.WithContext(ctx)
 
 	resp, err := client.Do(req)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	defer resp.Body.Close()
 
 	mfs, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
-	if want, got := 3, len(mfs); want != got {
-		t.Fatalf("unexpected number of metric families gathered, want %d, got %d", want, got)
-	}
+	require.NoError(t, err)
+	want, got := 3, len(mfs)
+	require.Equalf(t, want, got, "unexpected number of metric families gathered, want %d, got %d", want, got)
 	for _, mf := range mfs {
 		if len(mf.Metric) == 0 {
 			t.Errorf("metric family %s must not be empty", mf.GetName())
@@ -259,11 +246,10 @@ func TestClientMiddlewareAPI_WithRequestContext(t *testing.T) {
 		client_api_requests_total{code="200",method="get"} 1
 	`
 
-	if err := testutil.GatherAndCompare(reg, strings.NewReader(expected),
+	err = testutil.GatherAndCompare(reg, strings.NewReader(expected),
 		"client_api_requests_total",
-	); err != nil {
-		t.Fatal(err)
-	}
+	)
+	require.NoError(t, err)
 }
 
 func TestClientMiddlewareAPIWithRequestContextTimeout(t *testing.T) {
@@ -277,9 +263,7 @@ func TestClientMiddlewareAPIWithRequestContextTimeout(t *testing.T) {
 	defer backend.Close()
 
 	req, err := http.NewRequest("GET", backend.URL, nil)
-	if err != nil {
-		t.Fatalf("%v", err)
-	}
+	require.NoErrorf(t, err, "%v", err)
 
 	// Set a context with a short timeout.
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Millisecond)
@@ -287,13 +271,9 @@ func TestClientMiddlewareAPIWithRequestContextTimeout(t *testing.T) {
 	req = req.WithContext(ctx)
 
 	_, err = client.Do(req)
-	if err == nil {
-		t.Fatal("did not get timeout error")
-	}
+	require.Errorf(t, err, "did not get timeout error")
 	expectedMsg := "context deadline exceeded"
-	if !strings.Contains(err.Error(), expectedMsg) {
-		t.Fatalf("unexpected error: %q, expect error: %q", err.Error(), expectedMsg)
-	}
+	require.Containsf(t, err.Error(), expectedMsg, "unexpected error: %q, expect error: %q", err.Error(), expectedMsg)
 }
 
 func ExampleInstrumentRoundTripperDuration() {
diff --git a/prometheus/promhttp/instrument_server_test.go b/prometheus/promhttp/instrument_server_test.go
index 8aef09f70..68b5b7efe 100644
--- a/prometheus/promhttp/instrument_server_test.go
+++ b/prometheus/promhttp/instrument_server_test.go
@@ -21,6 +21,8 @@ import (
 	"net/http/httptest"
 	"testing"
 
+	"github.com/stretchr/testify/require"
+
 	"github.com/prometheus/client_golang/prometheus"
 )
 
@@ -451,9 +453,7 @@ func TestInstrumentTimeToFirstWrite(t *testing.T) {
 
 	d.WriteHeader(http.StatusOK)
 
-	if i != http.StatusOK {
-		t.Fatalf("failed to execute observeWriteHeader")
-	}
+	require.Equalf(t, http.StatusOK, i, "failed to execute observeWriteHeader")
 }
 
 // testResponseWriter is an http.ResponseWriter that also implements
diff --git a/prometheus/push/push_test.go b/prometheus/push/push_test.go
index d30d17550..4219d6b9b 100644
--- a/prometheus/push/push_test.go
+++ b/prometheus/push/push_test.go
@@ -22,6 +22,7 @@ import (
 	"testing"
 
 	"github.com/prometheus/common/expfmt"
+	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/client_golang/prometheus"
 )
@@ -42,9 +43,7 @@ func TestPush(t *testing.T) {
 			lastHeader = r.Header
 			var err error
 			lastBody, err = io.ReadAll(r.Body)
-			if err != nil {
-				t.Fatal(err)
-			}
+			require.NoError(t, err)
 			lastPath = r.URL.EscapedPath()
 			w.Header().Set("Content-Type", `text/plain; charset=utf-8`)
 			if r.Method == http.MethodDelete {
@@ -79,17 +78,13 @@ func TestPush(t *testing.T) {
 	reg.MustRegister(metric2)
 
 	mfs, err := reg.Gather()
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	buf := &bytes.Buffer{}
 	enc := expfmt.NewEncoder(buf, expfmt.NewFormat(expfmt.TypeProtoDelim))
 
 	for _, mf := range mfs {
-		if err := enc.Encode(mf); err != nil {
-			t.Fatal(err)
-		}
+		require.NoError(t, enc.Encode(mf))
 	}
 	wantBody := buf.Bytes()
 
diff --git a/prometheus/registry.go b/prometheus/registry.go
index c6fd2f58b..e25d7b835 100644
--- a/prometheus/registry.go
+++ b/prometheus/registry.go
@@ -26,12 +26,12 @@ import (
 	"sync"
 	"unicode/utf8"
 
-	"github.com/prometheus/client_golang/prometheus/internal"
-
 	"github.com/cespare/xxhash/v2"
 	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
 	"google.golang.org/protobuf/proto"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
 )
 
 const (
diff --git a/prometheus/registry_test.go b/prometheus/registry_test.go
index 35a74d282..9de8d28aa 100644
--- a/prometheus/registry_test.go
+++ b/prometheus/registry_test.go
@@ -31,13 +31,14 @@ import (
 	"testing"
 	"time"
 
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
-
 	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/expfmt"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 // uncheckedCollector wraps a Collector but its Describe method yields no Desc.
@@ -93,9 +94,7 @@ func testHandler(t testing.TB) {
 	}
 	externalBuf := &bytes.Buffer{}
 	enc := expfmt.NewEncoder(externalBuf, expfmt.NewFormat(expfmt.TypeProtoDelim))
-	if err := enc.Encode(externalMetricFamily); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, enc.Encode(externalMetricFamily))
 	externalMetricFamilyAsBytes := externalBuf.Bytes()
 	externalMetricFamilyAsText := []byte(`# HELP externalname externaldocstring
 # TYPE externalname counter
@@ -163,9 +162,7 @@ metric: <
 	}
 	buf := &bytes.Buffer{}
 	enc = expfmt.NewEncoder(buf, expfmt.NewFormat(expfmt.TypeProtoDelim))
-	if err := enc.Encode(expectedMetricFamily); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, enc.Encode(expectedMetricFamily))
 	expectedMetricFamilyAsBytes := buf.Bytes()
 	expectedMetricFamilyAsText := []byte(`# HELP name docstring
 # TYPE name counter
@@ -847,14 +844,10 @@ func TestAlreadyRegistered(t *testing.T) {
 
 	for _, s := range scenarios {
 		t.Run(s.name, func(t *testing.T) {
-			var err error
 			reg := prometheus.NewRegistry()
-			if err = s.registerWith(reg).Register(s.originalCollector); err != nil {
-				t.Fatal(err)
-			}
-			if err = s.reRegisterWith(reg).Register(s.newCollector); err == nil {
-				t.Fatal("expected error when registering new collector")
-			}
+			require.NoError(t, s.registerWith(reg).Register(s.originalCollector))
+			err := s.reRegisterWith(reg).Register(s.newCollector)
+			require.Errorf(t, err, "expected error when registering new collector")
 			are := &prometheus.AlreadyRegisteredError{}
 			if errors.As(err, are) {
 				if are.ExistingCollector != s.originalCollector {
@@ -1072,19 +1065,13 @@ test_summary_count{name="foo"} 2
 	counter.With(prometheus.Labels{"name": "qux"}).Inc()
 
 	tmpfile, err := os.CreateTemp("", "prom_registry_test")
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	defer os.Remove(tmpfile.Name())
 
-	if err := prometheus.WriteToTextfile(tmpfile.Name(), registry); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, prometheus.WriteToTextfile(tmpfile.Name(), registry))
 
 	fileBytes, err := os.ReadFile(tmpfile.Name())
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 	fileContents := string(fileBytes)
 
 	if fileContents != expectedOut {
@@ -1169,9 +1156,7 @@ func TestAlreadyRegisteredCollision(t *testing.T) {
 		// set of sub-collectors, determined by their names and const label values.
 		if err := reg.Register(&collector); err != nil {
 			are := &prometheus.AlreadyRegisteredError{}
-			if !errors.As(err, are) {
-				t.Fatal(err)
-			}
+			require.ErrorAs(t, err, are)
 
 			previous := are.ExistingCollector.(*collidingCollector)
 			current := are.NewCollector.(*collidingCollector)
diff --git a/prometheus/summary.go b/prometheus/summary.go
index ac5203c6f..e90f116ca 100644
--- a/prometheus/summary.go
+++ b/prometheus/summary.go
@@ -22,9 +22,8 @@ import (
 	"sync/atomic"
 	"time"
 
-	dto "github.com/prometheus/client_model/go"
-
 	"github.com/beorn7/perks/quantile"
+	dto "github.com/prometheus/client_model/go"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
diff --git a/prometheus/summary_test.go b/prometheus/summary_test.go
index 440237206..3328e7fe4 100644
--- a/prometheus/summary_test.go
+++ b/prometheus/summary_test.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 )
 
 func TestSummaryWithDefaultObjectives(t *testing.T) {
@@ -483,14 +484,10 @@ func TestNewConstSummaryWithCreatedTimestamp(t *testing.T) {
 	createdTs := time.Unix(1719670764, 123)
 
 	s, err := NewConstSummaryWithCreatedTimestamp(metricDesc, 100, 200, quantiles, createdTs)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
 	var metric dto.Metric
-	if err := s.Write(&metric); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, s.Write(&metric))
 
 	if metric.Summary.CreatedTimestamp.AsTime().UnixMicro() != createdTs.UnixMicro() {
 		t.Errorf("Expected created timestamp %v, got %v", createdTs, &metric.Summary.CreatedTimestamp)
diff --git a/prometheus/testutil/promlint/promlint_test.go b/prometheus/testutil/promlint/promlint_test.go
index c60507c19..b4b93233f 100644
--- a/prometheus/testutil/promlint/promlint_test.go
+++ b/prometheus/testutil/promlint/promlint_test.go
@@ -20,6 +20,7 @@ import (
 	"testing"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/client_golang/prometheus/testutil/promlint"
 )
@@ -424,14 +425,11 @@ x_ounces 10
 			l := promlint.New(strings.NewReader(tt.in))
 
 			problems, err := l.Lint()
-			if err != nil {
-				t.Fatalf("unexpected error: %v", err)
-			}
-
-			if want, got := tt.problems, problems; !reflect.DeepEqual(want, got) {
-				t.Fatalf("unexpected problems:\n- want: %v\n-  got: %v",
-					want, got)
-			}
+			require.NoErrorf(t, err, "unexpected error: %v", err)
+
+			want, got := tt.problems, problems
+			require.Truef(t, reflect.DeepEqual(want, got), "unexpected problems:\n- want: %v\n-  got: %v",
+				want, got)
 		})
 	}
 }
@@ -776,14 +774,11 @@ func runTests(t *testing.T, tests []test) {
 			l := promlint.New(strings.NewReader(tt.in))
 
 			problems, err := l.Lint()
-			if err != nil {
-				t.Fatalf("unexpected error: %v", err)
-			}
-
-			if want, got := tt.problems, problems; !reflect.DeepEqual(want, got) {
-				t.Fatalf("unexpected problems:\n- want: %v\n-  got: %v",
-					want, got)
-			}
+			require.NoErrorf(t, err, "unexpected error: %v", err)
+
+			want, got := tt.problems, problems
+			require.Truef(t, reflect.DeepEqual(want, got), "unexpected problems:\n- want: %v\n-  got: %v",
+				want, got)
 		})
 	}
 }
@@ -791,14 +786,11 @@ func runTests(t *testing.T, tests []test) {
 func TestCustomValidations(t *testing.T) {
 	lintAndVerify := func(l *promlint.Linter, cv test) {
 		problems, err := l.Lint()
-		if err != nil {
-			t.Fatalf("unexpected error: %v", err)
-		}
+		require.NoErrorf(t, err, "unexpected error: %v", err)
 
-		if want, got := cv.problems, problems; !reflect.DeepEqual(want, got) {
-			t.Fatalf("unexpected problems:\n- want: %v\n-  got: %v",
-				want, got)
-		}
+		want, got := cv.problems, problems
+		require.Truef(t, reflect.DeepEqual(want, got), "unexpected problems:\n- want: %v\n-  got: %v",
+			want, got)
 	}
 
 	prob := []promlint.Problem{
diff --git a/prometheus/timer_test.go b/prometheus/timer_test.go
index a27912dbe..101cb0c0e 100644
--- a/prometheus/timer_test.go
+++ b/prometheus/timer_test.go
@@ -17,9 +17,8 @@ import (
 	"reflect"
 	"testing"
 
-	"google.golang.org/protobuf/proto"
-
 	dto "github.com/prometheus/client_model/go"
+	"google.golang.org/protobuf/proto"
 )
 
 func TestTimerObserve(t *testing.T) {
diff --git a/prometheus/value.go b/prometheus/value.go
index cc23011fa..c5169d09b 100644
--- a/prometheus/value.go
+++ b/prometheus/value.go
@@ -20,11 +20,11 @@ import (
 	"time"
 	"unicode/utf8"
 
-	"github.com/prometheus/client_golang/prometheus/internal"
-
 	dto "github.com/prometheus/client_model/go"
 	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
 )
 
 // ValueType is an enumeration of metric types that represent a simple value.
diff --git a/prometheus/vec_test.go b/prometheus/vec_test.go
index 89bd85429..29962728e 100644
--- a/prometheus/vec_test.go
+++ b/prometheus/vec_test.go
@@ -19,6 +19,7 @@ import (
 	"testing"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 )
 
 func TestDelete(t *testing.T) {
@@ -306,9 +307,7 @@ func testMetricVec(t *testing.T, vec *GaugeVec) {
 			copy(pair[:], metric.values)
 
 			var metricOut dto.Metric
-			if err := metric.metric.Write(&metricOut); err != nil {
-				t.Fatal(err)
-			}
+			require.NoError(t, metric.metric.Write(&metricOut))
 			actual := *metricOut.Gauge.Value
 
 			var actualPair [2]string
@@ -319,25 +318,17 @@ func testMetricVec(t *testing.T, vec *GaugeVec) {
 			// Test output pair against metric.values to ensure we've selected
 			// the right one. We check this to ensure the below check means
 			// anything at all.
-			if actualPair != pair {
-				t.Fatalf("unexpected pair association in metric map: %v != %v", actualPair, pair)
-			}
+			require.Equalf(t, actualPair, pair, "unexpected pair association in metric map: %v != %v", actualPair, pair)
 
-			if actual != float64(expected[pair]) {
-				t.Fatalf("incorrect counter value for %v: %v != %v", pair, actual, expected[pair])
-			}
+			require.False(t, actual != float64(expected[pair]), "incorrect counter value for %v: %v != %v", pair, actual, expected[pair])
 		}
 	}
 
-	if total != len(expected) {
-		t.Fatalf("unexpected number of metrics: %v != %v", total, len(expected))
-	}
+	require.Lenf(t, expected, total, "unexpected number of metrics: %v != %v", total, len(expected))
 
 	vec.Reset()
 
-	if len(vec.metricMap.metrics) > 0 {
-		t.Fatalf("reset failed")
-	}
+	require.Emptyf(t, vec.metricMap.metrics, "reset failed")
 }
 
 func TestMetricVecWithConstraints(t *testing.T) {
@@ -378,9 +369,7 @@ func testConstrainedMetricVec(t *testing.T, vec *GaugeVec, constrain func(string
 			copy(pair[:], metric.values)
 
 			var metricOut dto.Metric
-			if err := metric.metric.Write(&metricOut); err != nil {
-				t.Fatal(err)
-			}
+			require.NoError(t, metric.metric.Write(&metricOut))
 			actual := *metricOut.Gauge.Value
 
 			var actualPair [2]string
@@ -391,25 +380,17 @@ func testConstrainedMetricVec(t *testing.T, vec *GaugeVec, constrain func(string
 			// Test output pair against metric.values to ensure we've selected
 			// the right one. We check this to ensure the below check means
 			// anything at all.
-			if actualPair != pair {
-				t.Fatalf("unexpected pair association in metric map: %v != %v", actualPair, pair)
-			}
+			require.Equalf(t, actualPair, pair, "unexpected pair association in metric map: %v != %v", actualPair, pair)
 
-			if actual != float64(expected[pair]) {
-				t.Fatalf("incorrect counter value for %v: %v != %v", pair, actual, expected[pair])
-			}
+			require.False(t, actual != float64(expected[pair]), "incorrect counter value for %v: %v != %v", pair, actual, expected[pair])
 		}
 	}
 
-	if total != len(expected) {
-		t.Fatalf("unexpected number of metrics: %v != %v", total, len(expected))
-	}
+	require.Lenf(t, expected, total, "unexpected number of metrics: %v != %v", total, len(expected))
 
 	vec.Reset()
 
-	if len(vec.metricMap.metrics) > 0 {
-		t.Fatalf("reset failed")
-	}
+	require.Emptyf(t, vec.metricMap.metrics, "reset failed")
 }
 
 func TestCounterVecEndToEndWithCollision(t *testing.T) {
@@ -424,9 +405,7 @@ func TestCounterVecEndToEndWithCollision(t *testing.T) {
 	vec.WithLabelValues("!0IC=VloaY").Add(2)
 
 	m := &dto.Metric{}
-	if err := vec.WithLabelValues("77kepQFQ8Kl").Write(m); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, vec.WithLabelValues("77kepQFQ8Kl").Write(m))
 	if got, want := m.GetLabel()[0].GetValue(), "77kepQFQ8Kl"; got != want {
 		t.Errorf("got label value %q, want %q", got, want)
 	}
@@ -434,9 +413,7 @@ func TestCounterVecEndToEndWithCollision(t *testing.T) {
 		t.Errorf("got value %f, want %f", got, want)
 	}
 	m.Reset()
-	if err := vec.WithLabelValues("!0IC=VloaY").Write(m); err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, vec.WithLabelValues("!0IC=VloaY").Write(m))
 	if got, want := m.GetLabel()[0].GetValue(), "!0IC=VloaY"; got != want {
 		t.Errorf("got label value %q, want %q", got, want)
 	}
@@ -513,18 +490,14 @@ func testCurryVec(t *testing.T, vec *CounterVec) {
 		}
 		m := &dto.Metric{}
 		c1, err := vec.GetMetricWithLabelValues("1", "2", "3")
-		if err != nil {
-			t.Fatal("unexpected error getting metric:", err)
-		}
+		require.NoErrorf(t, err, "unexpected error getting metric")
 		c1.Write(m)
 		if want, got := 1., m.GetCounter().GetValue(); want != got {
 			t.Errorf("want %f as counter value, got %f", want, got)
 		}
 		m.Reset()
 		c2, err := vec.GetMetricWithLabelValues("11", "22", "33")
-		if err != nil {
-			t.Fatal("unexpected error getting metric:", err)
-		}
+		require.NoErrorf(t, err, "unexpected error getting metric")
 		c2.Write(m)
 		if want, got := 1., m.GetCounter().GetValue(); want != got {
 			t.Errorf("want %f as counter value, got %f", want, got)
@@ -710,9 +683,7 @@ func testConstrainedCurryVec(t *testing.T, vec *CounterVec, constraint func(stri
 		}
 		m := &dto.Metric{}
 		c1, err := vec.GetMetricWithLabelValues("1", "2", "3")
-		if err != nil {
-			t.Fatal("unexpected error getting metric:", err)
-		}
+		require.NoErrorf(t, err, "unexpected error getting metric")
 		c1.Write(m)
 		if want, got := 1., m.GetCounter().GetValue(); want != got {
 			t.Errorf("want %f as counter value, got %f", want, got)
@@ -726,9 +697,7 @@ func testConstrainedCurryVec(t *testing.T, vec *CounterVec, constraint func(stri
 		}
 		m.Reset()
 		c2, err := vec.GetMetricWithLabelValues("11", "22", "33")
-		if err != nil {
-			t.Fatal("unexpected error getting metric:", err)
-		}
+		require.NoErrorf(t, err, "unexpected error getting metric")
 		c2.Write(m)
 		if want, got := 1., m.GetCounter().GetValue(); want != got {
 			t.Errorf("want %f as counter value, got %f", want, got)
diff --git a/prometheus/wrap.go b/prometheus/wrap.go
index 25da157f1..efd8ec0b2 100644
--- a/prometheus/wrap.go
+++ b/prometheus/wrap.go
@@ -17,10 +17,10 @@ import (
 	"fmt"
 	"sort"
 
-	"github.com/prometheus/client_golang/prometheus/internal"
-
 	dto "github.com/prometheus/client_model/go"
 	"google.golang.org/protobuf/proto"
+
+	"github.com/prometheus/client_golang/prometheus/internal"
 )
 
 // WrapRegistererWith returns a Registerer wrapping the provided
diff --git a/prometheus/wrap_test.go b/prometheus/wrap_test.go
index d2b4e4c6d..007e9e53a 100644
--- a/prometheus/wrap_test.go
+++ b/prometheus/wrap_test.go
@@ -20,6 +20,7 @@ import (
 	"time"
 
 	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -277,9 +278,7 @@ func TestWrap(t *testing.T) {
 		t.Run(n, func(t *testing.T) {
 			reg := NewPedanticRegistry()
 			for _, c := range s.preRegister {
-				if err := reg.Register(c); err != nil {
-					t.Fatal("error registering with unwrapped registry:", err)
-				}
+				require.NoErrorf(t, reg.Register(c), "error registering with unwrapped registry")
 			}
 			preReg := WrapRegistererWithPrefix(s.prefix, reg)
 			lReg := WrapRegistererWith(s.labels, preReg)
@@ -306,9 +305,7 @@ func TestWrap(t *testing.T) {
 			if !s.gatherFails && err != nil {
 				t.Fatal("gathering failed:", err)
 			}
-			if len(wantMF) != len(gotMF) {
-				t.Fatalf("Expected %d metricFamilies, got %d", len(wantMF), len(gotMF))
-			}
+			require.Equalf(t, len(wantMF), len(gotMF), "Expected %d metricFamilies, got %d", len(wantMF), len(gotMF))
 			for i := range gotMF {
 				if !proto.Equal(gotMF[i], wantMF[i]) {
 					var want, got []string
@@ -335,7 +332,5 @@ func TestNil(t *testing.T) {
 	// A wrapped nil registerer should be treated as a no-op, and not panic.
 	c := NewCounter(CounterOpts{Name: "test"})
 	err := WrapRegistererWith(Labels{"foo": "bar"}, nil).Register(c)
-	if err != nil {
-		t.Fatal("registering failed:", err)
-	}
+	require.NoErrorf(t, err, "registering failed")
 }
diff --git a/tutorials/whatsup/internal/acceptance_test.go b/tutorials/whatsup/internal/acceptance_test.go
index 38533c495..57848a9b9 100644
--- a/tutorials/whatsup/internal/acceptance_test.go
+++ b/tutorials/whatsup/internal/acceptance_test.go
@@ -78,5 +78,4 @@ func TestAcceptance(t *testing.T) {
 	if gotErr {
 		fmt.Println("Got this response from ", fmt.Sprintf("http://localhost:%v", WhatsupPort), ":", metrics)
 	}
-
 }
diff --git a/tutorials/whatsup/main.go b/tutorials/whatsup/main.go
index 5943eefb0..15ebd4e72 100644
--- a/tutorials/whatsup/main.go
+++ b/tutorials/whatsup/main.go
@@ -73,7 +73,7 @@ func runMain(opts internal.Config) (err error) {
 	m := http.NewServeMux()
 	// Create HTTP handler for Prometheus metrics.
 	// TODO
-	//m.Handle("/metrics", ...
+	// m.Handle("/metrics", ...
 
 	promClient, err := api.NewClient(api.Config{
 		Client:  &http.Client{Transport: instrumentRoundTripper(nil, "prometheus", http.DefaultTransport)},