.ENV·File Extension

What is a .env file?

A .env file is a Environment File — Environment variables file for local application configuration.

In the mime-db registry it has no registered standard MIME type. When serving this file over HTTP, use a Content-Type that matches its actual format.

When served over HTTP, responses should set the following header:

# No standard MIME type is registered for .env

Common software that reads/writes .env:

• Configuration files
• Data interchange between systems
• API request and response payloads
• Logs and data exports

• Open the file with VS Code, make your changes and save.
• Most editors preserve the original formatting and encoding — avoid changing the charset.

• Create a new file and save it with the .env extension, or export this format from VS Code.

DATABASE_URL=postgres://localhost:5432/app
PORT=3001

• mime-db
• refnet data sources

Updated 2026-08-18