diff --git a/.vscode/settings.json b/.vscode/settings.json
index 898ec90f..68d55ed1 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,4 +1,4 @@
 {
   // Enable ESlint flat config support
-  "eslint.experimental.useFlatConfig": true
+  "eslint.useFlatConfig": true
 }
diff --git a/README.md b/README.md
index 69887d8c..13c8e3de 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@
 - **URL Shortening:** Compress your URLs to their minimal length.
 - **Analytics:** Monitor link analytics and gather insightful statistics.
 - **Serverless:** Deploy without the need for traditional servers.
-- **Customizable Slug:** Support for personalized slugs.
+- **Customizable Slug:** Support for personalized slugs and case sensitivity.
 - **🪄 AI Slug:** Leverage AI to generate slugs.
 - **Link Expiration:** Set expiration dates for your links.
 
diff --git a/components/dashboard/links/Editor.vue b/components/dashboard/links/Editor.vue
index 4f7fb3b6..d4eedddb 100644
--- a/components/dashboard/links/Editor.vue
+++ b/components/dashboard/links/Editor.vue
@@ -102,10 +102,12 @@ onMounted(() => {
   }
 })
 
+const { caseSensitive } = useRuntimeConfig()
+
 async function onSubmit(formData) {
   const link = {
     url: formData.url,
-    slug: formData.slug,
+    slug: caseSensitive ? formData.slug : formData.slug.toLowerCase(),
     ...(formData.optional || []),
     expiration: formData.optional?.expiration ? date2unix(formData.optional?.expiration, 'end') : undefined,
   }
diff --git a/components/home/Features.vue b/components/home/Features.vue
index d61d183f..c983a6db 100644
--- a/components/home/Features.vue
+++ b/components/home/Features.vue
@@ -23,7 +23,7 @@ const features = ref([
   {
     title: 'Customizable Slug',
     description:
-          'Support for personalized slugs.',
+          'Support for personalized slugs and case sensitivity.',
     icon: Paintbrush,
   },
   {
diff --git a/docs/faqs.md b/docs/faqs.md
index aa6cde5c..159536b8 100644
--- a/docs/faqs.md
+++ b/docs/faqs.md
@@ -32,3 +32,13 @@ Of course. Please set the environment variable `NUXT_HOME_URL` to your blog or o
 ## 5. Why can't I see statistics after deploying with NuxtHub?
 
 NuxtHub's ANALYTICS points to its dataset, you need to set the `NUXT_DATASET` environment variable to point to the same dataset.
+
+## 6. Why are links always case-insensitive?
+
+This is a feature of Sink. By default, we automatically convert all links to lowercase to avoid case-sensitive issues and improve usability. This ensures users don’t encounter errors due to accidental capitalization differences.
+
+However, you can disable this feature by setting the `NUXT_CASE_SENSITIVE` environment variable to `true`.
+
+### What happens when `NUXT_CASE_SENSITIVE` is `true`?
+
+Newly generated links will be case-sensitive, treating `MyLink` and `mylink` as distinct. Randomly generated slugs will include both uppercase and lowercase characters, offering a larger pool of unique combinations (but not user-friendly that why we default to non-case-sensitive).
diff --git a/nuxt.config.ts b/nuxt.config.ts
index 049414ac..30beb159 100644
--- a/nuxt.config.ts
+++ b/nuxt.config.ts
@@ -60,6 +60,7 @@ export default defineNuxtConfig({
     dataset: 'sink',
     aiModel: '@cf/meta/llama-3.1-8b-instruct',
     aiPrompt: `You are a URL shortening assistant, please shorten the URL provided by the user into a SLUG. The SLUG information must come from the URL itself, do not make any assumptions. A SLUG is human-readable and should not exceed three words and can be validated using regular expressions {slugRegex} . Only the best one is returned, the format must be JSON reference {"slug": "example-slug"}`,
+    caseSensitive: false,
     public: {
       previewMode: '',
       slugDefaultLength: '6',
diff --git a/schemas/link.ts b/schemas/link.ts
index fe74492a..763c650c 100644
--- a/schemas/link.ts
+++ b/schemas/link.ts
@@ -2,10 +2,15 @@ import { z } from 'zod'
 import { customAlphabet } from 'nanoid'
 
 const { slugRegex } = useAppConfig()
+const { caseSensitive } = useRuntimeConfig()
 
 const slugDefaultLength = +useRuntimeConfig().public.slugDefaultLength
 
-export const nanoid = (length: number = slugDefaultLength) => customAlphabet('23456789abcdefghjkmnpqrstuvwxyz', length)
+export function nanoid(length: number = slugDefaultLength) {
+  return caseSensitive
+    ? customAlphabet('23456789abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ', length)
+    : customAlphabet('23456789abcdefghjkmnpqrstuvwxyz', length)
+}
 
 export const LinkSchema = z.object({
   id: z.string().trim().max(26).default(nanoid(10)),
diff --git a/server/middleware/1.redirect.ts b/server/middleware/1.redirect.ts
index 297098d9..aeebad33 100644
--- a/server/middleware/1.redirect.ts
+++ b/server/middleware/1.redirect.ts
@@ -5,7 +5,7 @@ import type { LinkSchema } from '@/schemas/link'
 export default eventHandler(async (event) => {
   const { pathname: slug } = parsePath(event.path.replace(/^\/|\/$/g, '')) // remove leading and trailing slashes
   const { slugRegex, reserveSlug } = useAppConfig(event)
-  const { homeURL, linkCacheTtl, redirectWithQuery } = useRuntimeConfig(event)
+  const { homeURL, linkCacheTtl, redirectWithQuery, caseSensitive } = useRuntimeConfig(event)
   const { cloudflare } = event.context
 
   if (event.path === '/' && homeURL)
@@ -13,7 +13,21 @@ export default eventHandler(async (event) => {
 
   if (slug && !reserveSlug.includes(slug) && slugRegex.test(slug) && cloudflare) {
     const { KV } = cloudflare.env
-    const link: z.infer<typeof LinkSchema> | null = await KV.get(`link:${slug}`, { type: 'json', cacheTtl: linkCacheTtl })
+
+    let link: z.infer<typeof LinkSchema> | null = null
+
+    const getLink = async (key: string) =>
+      await KV.get(`link:${key}`, { type: 'json', cacheTtl: linkCacheTtl })
+
+    link = await getLink(slug)
+
+    // fallback to lowercase slug if caseSensitive is false and the slug is not found
+    const lowerCaseSlug = slug.toLowerCase()
+    if (!caseSensitive && !link && lowerCaseSlug !== slug) {
+      console.log('lowerCaseSlug fallback:', `slug:${slug} lowerCaseSlug:${lowerCaseSlug}`)
+      link = await getLink(lowerCaseSlug)
+    }
+
     if (link) {
       event.context.link = link
       try {