DevPilot
web-development·September 21, 2026·1 min read

Deploying a Next.js App to Vercel with Environment Variables

A practical guide to deploying Next.js applications on Vercel with proper environment configuration.

deploymentvercelnextjsenvironment-variables

Deploying a Next.js App to Vercel with Environment Variables

Vercel integrates tightly with Next.js but requires careful environment setup.

Problem

Missing environment variables cause build or runtime errors on Vercel that don't appear locally.

Working approach

  • Define variables in .env.local for development.
  • Add production variables in the Vercel project settings.
  • Reference variables using process.env only where needed.

See troubleshooting/databases/database-connection-production for diagnosing database connection failures that share the same root cause: differences between local persistent servers and serverless execution environments (see deployment environment variables).

Verification

Run a preview deployment and check the Vercel function logs for missing variable errors.