: Variables explicitly set in the terminal environment (e.g., API_KEY=123 npm run build ) or injected directly by hosting platforms like Vercel, Netlify, or AWS.
Commit this file to your repository.
: A common scenario is when a developer needs to test a production build locally but wants to connect to a specific local staging database instead of the global production one. Comparisons with Other Files Committed to Git? .env Default values for all environments. .env.production General production settings for all servers. .env.local Local overrides for all environments (dev & prod). No .env.local.production Local overrides for only production mode. No Best Practices .env.local.production
Environment variables are values that are set outside of your application code but are used by your application to configure its behavior. They can be used to store sensitive information such as API keys, database credentials, or encryption secrets. Environment variables can also be used to configure application settings, such as debug modes or feature flags.
To understand why this specific file exists, it helps to look at the naming convention used by frameworks (most notably Next.js): : Variables explicitly set in the terminal environment (e
Do not accidentally put highly sensitive credentials (like private database passwords) into variables prefixed for the client side within your .env.local.production file. Summary Comparison Commit to Git? Environment Context .env Default settings for all environments .env.local Local overrides for all environments .env.production Production defaults for the whole team Production only .env.local.production Local production overrides on your machine No Production only
When running in ( NODE_ENV=development ), you will get the database settings from the combined sources: the host and port come from .env , while the user and password come from .env.local , and the database name is from .env.development . Comparisons with Other Files Committed to Git
.env.local.production is a file intended to hold environment variables that are loaded when a developer is running a "production" build on their local machine . The Hierarchy of Environment Variables
API_URL="http://localhost:4000" # Overrides the API_URL from .env.production for local production testing. SOME_SECRET_KEY="a-real-secret-key" # A secret for local prod test.
For production builds, the .env.production.local file is specifically designed for . It should never exist on a production server. Production secrets are injected by the platform at runtime and take the highest priority over any file.
The framework will detect NODE_ENV=production and automatically load the variables from .env.local.production to override .env.production . Differences: .env.local vs .env.local.production Primary Use Case .env.local All Environments Machine-specific dev secrets. .env.local.production Local Production Only Testing production APIs locally. Conclusion
