vercel/next.js / errors / deploymentid-not-a-string.mdx

---

title: 'deploymentId must be a string'

Why This Error Occurred

The deploymentId option in your next.config.js must be a string value.

Possible Ways to Fix It

Ensure your deploymentId is a string:

// ✅ Correct
module.exports = {
  deploymentId: 'my-deployment-123',
}

// ✅ Using environment variables
module.exports = {
  deploymentId: process.env.GIT_HASH || 'default-id',
}

// ❌ Incorrect
module.exports = {
  deploymentId: 12345, // Must be a string, not a number
}

The deploymentId can be:

• A string: deploymentId: 'my-deployment-123'
• undefined (will use NEXT_DEPLOYMENT_ID environment variable if set)