It belongs to the family of .env files which allow you to separate code from configuration. Unlike .env or .env.development , the .local suffix implies that the file should be checked into version control (e.g., Git). The Hierarchy of Environment Files
Environment-specific configuration is a common challenge in software development. Different environments require distinct settings, such as database connections, API keys, and server configurations. Hardcoding these settings directly into the application code can lead to errors, security vulnerabilities, and difficulties in maintaining and scaling the application. To address this issue, developers often use environment files, which store configuration settings specific to each environment.
Understanding .env.development.local : The Ultimate Guide to Local Environment Variables .env.development.local
: Specifies the environment mode. These variables will only load when your application is running in development mode (usually triggered by NODE_ENV=development ).
From to lowest priority , the hierarchy typically looks like this: It belongs to the family of
The most critical step is ensuring that all .local files are excluded from version control. Add the following lines to your .gitignore file:
Because of the "server-only" import, if any client component tries to import this file, the Next.js build will fail, preventing a security leak. Understanding
Therefore, The Environment File Hierarchy
:
Variables intended for the browser must be prefixed with NEXT_PUBLIC_ : NEXT_PUBLIC_API_URL=https://localhost:3000 2. Vite (React, Vue, Svelte)
Environment files are only read when the local server boots up. If you add a variable to .env.development.local , you must stop ( Ctrl + C ) and restart your development server.