Deploying to Vercel: A Complete Guide for Next.js Applications
Vercel is the easiest way to deploy Next.js applications, but there are production considerations that the quick-start docs do not cover. Here is everything I have learned.
Deploying to Vercel: A Complete Guide for Next.js Applications
Vercel makes deploying Next.js applications remarkably simple — push to GitHub and your app is live. But simple to start does not mean simple to run well in production. Here is everything I have learned deploying multiple Next.js applications to Vercel.
The Basics: First Deployment
If you have a Next.js app on GitHub, deploying to Vercel takes about two minutes:
- Go to vercel.com and sign in with GitHub
- Click "New Project" and import your repository
- Configure environment variables
- Click "Deploy"
Vercel auto-detects Next.js and configures the build correctly. Every push to your main branch triggers a new production deployment. Every pull request gets a preview deployment with its own unique URL.
Environment Variables
The most common first mistake: forgetting to set environment variables in Vercel that you have in your local .env file.
Go to your project settings in Vercel and add every environment variable your application needs. Critical distinction:
- Variables prefixed with
NEXT_PUBLIC_are embedded in the client-side bundle and visible to anyone who inspects your JavaScript. Use these only for non-sensitive values like your API base URL. - All other variables are server-only and never reach the client. Use these for API keys, database connection strings, and JWT secrets.
Never put sensitive values in NEXT_PUBLIC_ variables.
For Work Log Pro and my portfolio, I have separate environment variable sets for preview deployments (pointing to a staging database) and production deployments (pointing to the production database). Vercel supports this natively through its environment variable scoping.
Build Configuration
If your Next.js build fails on Vercel but works locally, the most common cause is an environment variable missing at build time. Some Next.js code runs during — database connections, API key validations, dynamic imports.