.env.local.production

: General default variables loaded in all environments (committed to git). Why this hierarchy matters

When your application builds for production ( npm run build ), the build tool scans these files in order. If a variable like API_URL is defined in both .env.production and .env.local.production , the value in .env.local.production takes precedence. When to Use .env.local.production

What are you currently using (e.g., Next.js Pages Router or App Router)?

The main reason .env files sometimes get committed is that they contain a mix of safe defaults (like APP_NAME=MyApp ) and secrets. The solution is to in the first place. .env.local.production

Note that if you use a src directory, these .env.* files must always go in the , alongside package.json , not inside the src directory.

(Variables set directly on the server/terminal)

You might wonder why you wouldn't just use .env.production . The answer lies in the distinction between and sensitive secrets . 1. Security and Secrets : General default variables loaded in all environments

If you are using a framework like Next.js or Vite, environment variable loading is built-in. For a plain Node.js project, you would install dotenv :

The file follows standard KEY=VALUE syntax. Depending on your framework, public variables meant for the browser require specific prefixes, while private variables do not. Here is an example configuration for a Next.js application:

Because .env.local.production is ignored by git, other developers on your team won't know it exists or what variables it requires. Always maintain a .env.example file that lists the keys (but leaves the values blank or uses placeholders): When to Use

Strictly speaking, .env.local.production is in any major framework's official documentation. The convention set by tools like Create React App, Next.js, and dotenv-flow uses either .env.[environment].local (e.g., .env.development.local , .env.production.local ) or the standard .env.local file. The ordering of the segments matters: the environment name typically comes before the .local suffix, not the other way around.

You log an API key, commit, and push. It's now in your Git history forever.

This article provides an in-depth look at what .env.local.production is, how it fits into the environment variable hierarchy, when to use it, and best practices for keeping your production secrets secure. What is .env.local.production ?

: Specifies a local override . This file is machine-specific and is designed to bypass the default, committed environment settings.

: The base file used to load environment variables into your application framework.