Environment Variables in Next.js

Variable Naming

Next.js has specific rules for environment variable exposure:

• Server-only: Any variable (no prefix required)
• Client-exposed: Must be prefixed with NEXT_PUBLIC_
• System variables: NODE_ENV, VERCEL_* are automatically available

File Structure

.env.local          # Local overrides (gitignored)
.env.development    # Development defaults
.env.production     # Production defaults
.env                # Defaults (committed)