Troubleshooting

A quick reference for the most common issues.

My build failed

• Open the Logs tab and read the build output — the error is usually near the end.
• Confirm the app builds locally with the same install/build commands.
• Make sure any required environment variables are set, including build-time variables like NEXT_PUBLIC_*.

My app deploys but returns errors

• Check the runtime logs in the Logs tab for stack traces.
• Verify your start command and that the app listens on the expected port.
• Confirm your database connection string is set correctly as an environment variable.

My custom domain isn't working

• Make sure you created the exact DNS record shown on the Domains tab.
• DNS changes can take time to propagate — wait for the record's TTL and retry.
• See Custom domains & SSL.

The first request is slow

On the Free plan, apps scale to zero when idle, so the first request after a quiet period wakes the app and is slower. Upgrade to a paid plan to keep apps warm.

My database won't connect

• Confirm the connection string is correct and stored as an environment variable.
• Check that you redeployed after adding or changing the variable.
• See Connecting to a database.