You cannot use different slug names for the same dynamic path Next.js Origin: On your device OSI layer 7 · Application Last updated 5 Nov 2026

Next.js: Error: You cannot use different slug names for the same dynamic path ('id' !== 'slug')

Sibling dynamic folders at the same level use different parameter names.

Exact message you may see You cannot use different slug names for the same dynamic path ('id' !== 'slug')Error: You cannot use different slug names for the same dynamic pathdifferent slug names for the same dynamic path
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Seen on: Next.js

Meaning

At one path level only one dynamic segment name is allowed: [id] and [slug] can't coexist. Rename them to the same name, nest them differently, or merge routes. After renaming restart next dev and clear .next.

Common causes

  • app/posts/[id] and app/posts/[slug] both present
  • Pages and app routes with different names for the same segment
  • Leftover renamed folder
  • Catch-all conflicts
  • Copy-paste folder

⚡ Quick fix

  1. Rename to a single consistent param name
  2. Remove the stale folder
  3. Restart dev server and delete .next

Detailed fix by platform

Linux

  1. rm -rf .next && npm run dev after renaming folders

How to diagnose

  1. Folders — Both [id] and [slug]?
  2. Level — Same parent?
  3. Cache — .next cleared?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: On your device. Errors that are often confused with or caused by this one (click to open):

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