diff --git a/docs/configuration.md b/docs/configuration.md
index a6be688..1f3a891 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -43,3 +43,11 @@ Default prompt:
 ```txt
 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"}
 ```
+
+## `NUXT_CASE_SENSITIVE`
+
+Set URL case sensitivity.
+
+## `NUXT_LIST_QUERY_LIMIT`
+
+Set the maximum query data volume for the Metric list.
diff --git a/docs/faqs.md b/docs/faqs.md
index 159536b..1b99866 100644
--- a/docs/faqs.md
+++ b/docs/faqs.md
@@ -42,3 +42,7 @@ However, you can disable this feature by setting the `NUXT_CASE_SENSITIVE` envir
 ### 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).
+
+## 7. Why does the Metric list only show the top 500 data entries?
+
+To improve query performance, we have limited the amount of data. If you need to query more data, you can adjust it through `NUXT_LIST_QUERY_LIMIT`.
diff --git a/schemas/link.ts b/schemas/link.ts
index bae2041..c27397e 100644
--- a/schemas/link.ts
+++ b/schemas/link.ts
@@ -2,15 +2,10 @@ import { customAlphabet } from 'nanoid'
 import { z } from 'zod'
 
 const { slugRegex } = useAppConfig()
-const { caseSensitive } = useRuntimeConfig()
 
 const slugDefaultLength = +useRuntimeConfig().public.slugDefaultLength
 
-export function nanoid(length: number = slugDefaultLength) {
-  return caseSensitive
-    ? customAlphabet('23456789abcdefghjkmnpqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ', length)
-    : customAlphabet('23456789abcdefghjkmnpqrstuvwxyz', length)
-}
+export const nanoid = (length: number = slugDefaultLength) => customAlphabet('23456789abcdefghjkmnpqrstuvwxyz', length)
 
 export const LinkSchema = z.object({
   id: z.string().trim().max(26).default(nanoid(10)),
diff --git a/server/api/link/create.post.ts b/server/api/link/create.post.ts
index 7797220..e3be9b1 100644
--- a/server/api/link/create.post.ts
+++ b/server/api/link/create.post.ts
@@ -3,6 +3,12 @@ import { LinkSchema } from '@/schemas/link'
 export default eventHandler(async (event) => {
   const link = await readValidatedBody(event, LinkSchema.parse)
 
+  const { caseSensitive } = useRuntimeConfig(event)
+
+  if (!caseSensitive) {
+    link.slug = link.slug.toLowerCase()
+  }
+
   const { cloudflare } = event.context
   const { KV } = cloudflare.env
   const existingLink = await KV.get(`link:${link.slug}`)
diff --git a/server/middleware/1.redirect.ts b/server/middleware/1.redirect.ts
index bafe5cc..524869c 100644
--- a/server/middleware/1.redirect.ts
+++ b/server/middleware/1.redirect.ts
@@ -19,13 +19,13 @@ export default eventHandler(async (event) => {
     const getLink = async (key: string) =>
       await KV.get(`link:${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()
+    link = await getLink(caseSensitive ? slug : lowerCaseSlug)
+
+    // fallback to original slug if caseSensitive is false and the slug is not found
     if (!caseSensitive && !link && lowerCaseSlug !== slug) {
-      console.log('lowerCaseSlug fallback:', `slug:${slug} lowerCaseSlug:${lowerCaseSlug}`)
-      link = await getLink(lowerCaseSlug)
+      console.log('original slug fallback:', `slug:${slug} lowerCaseSlug:${lowerCaseSlug}`)
+      link = await getLink(slug)
     }
 
     if (link) {