IT Error Decoder
Vercel

How to Fix Vercel deploy hangs at 'Building'

Last reviewed

Error message

Vercel deployment is stuck on 'Building' for more than 10 minutes with no log output.

Hung builds are the worst kind to debug because there's no error to read. Cancel and reproduce locally with verbose logging.

What this error means

The build started but isn't producing any new log output. Either it's running an extremely slow step, or it's deadlocked.

Why this happens

Common causes: a build step waiting on user input, an infinite loop in a build script, network call to a service that hangs forever, or a watch-mode dev server accidentally being run instead of a build.

Quick fix (for end users)

  • Cancel the deployment from the Vercel dashboard.
  • Trigger a new deploy after the next commit and watch the log.

Admin / engineer fix

  • Reproduce locally with verbose flags.

    command
    VERCEL_DEBUG=1 npm run build

  • Check for build scripts that wait on stdin (rare but devastating).

  • Make sure your build script is `next build`, not `next dev` — `next dev` will run forever.

Step-by-step fix

  1. Cancel the stuck deployment.

  2. Reproduce locally to find what hangs.

  3. Fix and redeploy.

Affected products

Vercel

Common variations of this error

People also see these phrasings of the same problem:

  • Vercel deployment never finishes

Still broken? Try these

  • Check that the build script doesn't have circular dependencies in npm scripts.
  • If using Husky pre-build hooks, ensure they don't prompt for input.

Related errors

Related searches

  • vercel build hangs
  • vercel deployment stuck

Frequently asked questions

What does "Vercel deploy hangs at 'Building'" mean?

The build started but isn't producing any new log output. Either it's running an extremely slow step, or it's deadlocked.

What causes "Vercel deploy hangs at 'Building'"?

Common causes: a build step waiting on user input, an infinite loop in a build script, network call to a service that hangs forever, or a watch-mode dev server accidentally being run instead of a build.

How do I fix "Vercel deploy hangs at 'Building'"?

1. Cancel the stuck deployment. 2. Reproduce locally to find what hangs. 3. Fix and redeploy. Always test changes in a non-production environment first.

Browse more errors in Vercel: Fix Vercel deployment errors. Build failures, missing output directories, exceeded build duration, missing env vars, and module resolution issues. Or paste your own error into the error decoder tool to find a match. You can also go back to the homepage to browse common errors by topic.