diff --git a/src/Illuminate/Support/Stringable.php b/src/Illuminate/Support/Stringable.php
index b0f194fa6e0b..c18ef686fa0a 100644
--- a/src/Illuminate/Support/Stringable.php
+++ b/src/Illuminate/Support/Stringable.php
@@ -1194,6 +1194,30 @@ public function whenIsAscii($callback, $default = null)
         return $this->when($this->isAscii(), $callback, $default);
     }
 
+    /**
+     * Execute the given callback if the string is a valid JSON string.
+     *
+     * @param  callable  $callback
+     * @param  callable|null  $default
+     * @return static
+     */
+    public function whenJson($callback, $default = null)
+    {
+        return $this->when($this->isJson(), $callback, $default);
+    }
+
+    /**
+     * Execute the given callback if the string is not a valid JSON string.
+     *
+     * @param  callable  $callback
+     * @param  callable|null  $default
+     * @return static
+     */
+    public function whenNotJson($callback, $default = null)
+    {
+        return $this->when(! $this->isJson(), $callback, $default);
+    }
+
     /**
      * Execute the given callback if the string is a valid UUID.
      *
diff --git a/tests/Support/SupportStringableTest.php b/tests/Support/SupportStringableTest.php
index c6fb80f01ddf..c98e39912ed6 100644
--- a/tests/Support/SupportStringableTest.php
+++ b/tests/Support/SupportStringableTest.php
@@ -350,6 +350,32 @@ public function testWhenIsAscii()
         }));
     }
 
+    public function testWhenJson()
+    {
+        $this->assertSame('JSON: 1', (string) $this->stringable('1')->whenJson(function ($stringable) {
+            return $stringable->prepend('JSON: ');
+        }, function ($stringable) {
+            return $stringable->prepend('Not JSON: ');
+        }));
+
+        $this->assertSame('Not JSON: 1,', (string) $this->stringable('1,')->whenJson(function ($stringable) {
+            return $stringable->prepend('JSON: ');
+        }, function ($stringable) {
+            return $stringable->prepend('Not JSON: ');
+        }));
+    }
+
+    public function testWhenNotJson()
+    {
+        $this->assertSame('[1,2,3]', (string) $this->stringable('[1,2,3]')->whenNotJson(function ($stringable) {
+            return $stringable.' JSON';
+        }));
+
+        $this->assertSame('Not JSON', (string) $this->stringable('Not')->whenNotJson(function ($stringable) {
+            return $stringable.' JSON';
+        }));
+    }
+
     public function testWhenIsUuid()
     {
         $this->assertSame('Uuid: 2cdc7039-65a6-4ac7-8e5d-d554a98e7b15', (string) $this->stringable('2cdc7039-65a6-4ac7-8e5d-d554a98e7b15')->whenIsUuid(function ($stringable) {