Vercel deploy fails: Command "npm run build" exited with 1

What it means

"Exited with 1" just means the build failed. It isn't the real error. The real one is a few lines higher up in the build log.

Why AI tools cause it

• Type errors. TypeScript checks run during the build and stop it, even if the app looked fine in development.
• Lint errors stop some builds (older Next.js versions and some Vite setups run a linter during build).
• A missing file or package: see our "Module not found" fix.
• A missing environment variable that the code reads while building.
• A different Node version on Vercel than on your computer.

The fix

1. In Vercel, open the failed deployment and scroll the Build Logs up from the bottom to the first red error. That's the one to fix.
2. Run npm run build on your own computer. It should fail the same way, so you can fix it faster.
3. Fix the error it names. Don't switch off type checking to get past it: those errors usually point at real bugs.
4. If it's about an environment variable, add it in Settings → Environment Variables and redeploy.
5. If it mentions Node, set the same major version in Settings → Build and Deployment → Node.js Version, or add "engines": { "node": "24.x" } to package.json (this overrides the setting). Vercel only supports recent Node versions, so if yours is older locally, upgrade it.

Paste this into your AI

My Vercel deploy fails with 'Command "npm run build" exited with 1'. Here is the first error in the build log: <paste it>. Fix the cause properly, without disabling TypeScript or lint checks, then run npm run build locally and confirm it passes.

Still broken?

If it builds locally but not on Vercel, clear the build cache: redeploy and untick Use existing Build Cache.