.env.development.local May 2026

.env.development.local file is a specialized configuration file used in modern web development frameworks like Create React App

This article is a deep exploration of what .env.development.local is, why it exists, how it interacts with other .env files, and crucially, how to use it without accidentally leaking sensitive data to your production environment or version control system. .env.development.local

Example of a dotenv configuration file:

Crucial Rule: Later files override earlier files. If the same variable exists in .env and .env.development.local, the value in .env.development.local takes precedence. why it exists