How to Fix Vercel build fails with TypeScript 'Type error'

What this error means

Your Vercel build invoked TypeScript and the type checker found an error. Vercel's default Next.js build fails on type errors, even if the app runs locally.

Why this happens

Drift between local and CI: missing types, looser local tsconfig, packages with mismatched versions, or types changed in a transitive dependency.

Step-by-step fix

1. 1

   Reproduce the exact CI build locally.

   commandCopy

   rm -rf node_modules .next && npm ci && npm run build

2. 2

   Fix the underlying type error rather than ignoring it. Read the file:line reported in the build log.

3. 3

   If you must ship despite a type error temporarily, set `typescript.ignoreBuildErrors = true` in `next.config.mjs` — but track it and remove it.

   commandCopy

   // next.config.mjs (temporary escape hatch)
   const nextConfig = {
     typescript: { ignoreBuildErrors: true },
   };

4. 4

   Pin your Node and TypeScript versions in `package.json` `engines` so CI matches your laptop.

Still broken? Try these

• Check that `tsconfig.json` is the same locally and on Vercel (no .gitignored override).
• If using path aliases, confirm `paths` in tsconfig matches the import in source.
• Run `npx tsc --noEmit` locally — that's exactly what Next.js runs in production builds.

Related errors

• Vercel
  Vercel build fails with 'Module not found'
• Vercel
  No Output Directory named "public" found after the Build completed

Frequently asked questions