diff --git a/apps/api/src/routes/content/collections.ts b/apps/api/src/routes/content/collections.ts
index a7698c5..b6219cd 100644
--- a/apps/api/src/routes/content/collections.ts
+++ b/apps/api/src/routes/content/collections.ts
@@ -1,8 +1,8 @@
 import type { FastifyPluginAsync } from "fastify";
-import { env } from "@playfulprogramming/common";
 import { db, posts } from "@playfulprogramming/db";
 import { Type, type Static } from "typebox";
 import { eq } from "drizzle-orm";
+import { createImageUrl } from "../../utils.ts";
 
 const CollectionsQueryParamsSchema = Type.Object({
 	locale: Type.String({ default: "en" }),
@@ -71,11 +71,6 @@ const CollectionsResponseSchema = Type.Array(
 
 type CollectionsResponse = Static<typeof CollectionsResponseSchema>;
 
-function createImageUrl(path: string): string {
-	const s3PublicUrl = `${env.S3_PUBLIC_URL}/${env.S3_BUCKET}/`;
-	return new URL(path, s3PublicUrl).toString();
-}
-
 const collectionsRoutes: FastifyPluginAsync = async (fastify) => {
 	fastify.get<{
 		Querystring: Static<typeof CollectionsQueryParamsSchema>;
diff --git a/apps/api/src/routes/tasks/post-images.ts b/apps/api/src/routes/tasks/post-images.ts
index 47c29cb..c79f993 100644
--- a/apps/api/src/routes/tasks/post-images.ts
+++ b/apps/api/src/routes/tasks/post-images.ts
@@ -1,5 +1,4 @@
 import type { FastifyPluginAsync } from "fastify";
-import { env } from "@playfulprogramming/common";
 import { db } from "@playfulprogramming/db";
 import { Type, type Static } from "typebox";
 import {
@@ -7,6 +6,7 @@ import {
 	Tasks,
 	createJob,
 } from "@playfulprogramming/bullmq";
+import { createImageUrl } from "../../utils.ts";
 
 const PostImageRequestSchema = Type.Object(
 	{
@@ -49,13 +49,10 @@ const PostImagesResponseSchema = Type.Object(
 function mapPostImages(
 	result: PostImageOutput,
 ): Static<typeof PostImagesResponseSchema> {
-	const s3PublicUrl = `${env.S3_PUBLIC_URL}/${env.S3_BUCKET}/`;
 	return {
-		banner: result.bannerKey
-			? new URL(result.bannerKey, s3PublicUrl).toString()
-			: undefined,
+		banner: result.bannerKey ? createImageUrl(result.bannerKey) : undefined,
 		linkPreview: result.linkPreviewKey
-			? new URL(result.linkPreviewKey, s3PublicUrl).toString()
+			? createImageUrl(result.linkPreviewKey)
 			: undefined,
 	};
 }
diff --git a/apps/api/src/routes/tasks/url-metadata.ts b/apps/api/src/routes/tasks/url-metadata.ts
index 4513226..27ca3de 100644
--- a/apps/api/src/routes/tasks/url-metadata.ts
+++ b/apps/api/src/routes/tasks/url-metadata.ts
@@ -1,5 +1,4 @@
 import type { FastifyPluginAsync } from "fastify";
-import { env } from "@playfulprogramming/common";
 import { db } from "@playfulprogramming/db";
 import { Type, type Static } from "typebox";
 import {
@@ -8,6 +7,7 @@ import {
 	UrlMetadataInputSchema,
 	createJob,
 } from "@playfulprogramming/bullmq";
+import { createImageUrl } from "../../utils.ts";
 
 type UrlMetadataDbResult = NonNullable<
 	Awaited<ReturnType<typeof db.query.urlMetadata.findFirst>>
@@ -106,11 +106,6 @@ const UrlMetadataResponseSchema = Type.Object(
 	},
 );
 
-function mapObjectKey(key: string): string {
-	const s3PublicUrl = `${env.S3_PUBLIC_URL}/${env.S3_BUCKET}/`;
-	return new URL(key, s3PublicUrl).toString();
-}
-
 function mapImageData(
 	key: string | null,
 	width: number | null,
@@ -119,7 +114,7 @@ function mapImageData(
 ): Static<typeof ImageSchema> | undefined {
 	if (!key) return undefined;
 	return {
-		src: mapObjectKey(key),
+		src: createImageUrl(key),
 		width: width || undefined,
 		height: height || undefined,
 		altText: altText || undefined,
@@ -143,7 +138,7 @@ async function mapEmbedGist(
 		description: gist.description || undefined,
 		files: gistFiles.map((file) => ({
 			filename: file.filename,
-			contentUrl: mapObjectKey(file.contentKey),
+			contentUrl: createImageUrl(file.contentKey),
 			language: file.language,
 		})),
 	};
diff --git a/apps/api/src/utils.ts b/apps/api/src/utils.ts
new file mode 100644
index 0000000..cced857
--- /dev/null
+++ b/apps/api/src/utils.ts
@@ -0,0 +1,16 @@
+import { env } from "@playfulprogramming/common";
+
+/** Removes leading and trailing slashes from a string. */
+function trimSlashes(input: string): string {
+	return input.replace(/^\/+|\/+$/g, "");
+}
+
+const S3_BASE_URL = `${trimSlashes(env.S3_PUBLIC_URL)}/${trimSlashes(env.S3_BUCKET)}/`;
+/**
+ * Constructs a full S3 image URL from a relative path.
+ * @param path The relative path to the image.
+ * @returns The absolute URL to the image.
+ */
+export function createImageUrl(path: string): string {
+	return new URL(trimSlashes(path), S3_BASE_URL).toString();
+}