← All errors · Next.jsVercel build & deploy errors

Module not found: Can't resolve '...'

Exact error

Module not found: Can't resolve 'some-package'

What it means

The bundler could not locate an imported file or package.

Likely causes

• The package isn't installed (or is only installed locally, not in package.json).
• Wrong relative path or wrong letter case (works on macOS/Windows, fails on Linux/Vercel).
• A path alias like @/ not configured in tsconfig/jsconfig.
• A Node-only module (fs, path) imported into client code.

How to fix it

1. Install the package and make sure it is saved to package.json:

   npm install some-package

2. Check the exact file name casing matches the import. Linux filesystems are case-sensitive. To fix a case-only rename in git:

   git mv components/button.tsx components/Button.tsx

3. If you use the @/ alias, confirm it exists:

   // tsconfig.json
   { "compilerOptions": { "baseUrl": ".", "paths": { "@/*": ["./*"] } } }

4. Only import fs/path in server code (Server Components, route handlers, getStaticProps).

Prevent this next time

• Add a CI job that runs `npm ci && npm run build` on every push, mirroring a clean Vercel build.
• Pin your Node.js version in package.json `engines` and commit your lockfile.

Guide: catch outages before your users do.

Related errors

• Command "npm run build" exited with 1
• Works locally but fails on Vercel