What is .env?
A .env file is a simple text file containing key-value pairs of environment variables. It is used to configure applications by injecting settings (like API keys, database URLs, and debug flags) into the environment at runtime.
This quick guide explains when to use .env files, how to open them on any device, and how to share them instantly with FileXhost.
When to use .env files
- You need to store sensitive information like API keys or database passwords.
- You want to configure your app differently for development, staging, and production.
- You are following the '12-Factor App' methodology for configuration.
How to open .env files
These are plain text files. You can open them in any code editor (VS Code, Sublime Text, Vim).
Algorithm details
The format is extremely simple: `KEY=VALUE`. Lines starting with `#` are comments. Values can sometimes be quoted, but it's not strictly required by all parsers.
Browser & platform support
- Security Warning: .env files should NEVER be accessible publicly in a browser. They contain secrets.
- FileXhost: We serve them as text/plain for sharing/educational purposes, but ensure no real secrets are shared.
Format comparison
| Feature | Details |
|---|---|
| Security | Designed to be kept out of version control (should always be in .gitignore). |
| Simplicity | The simplest possible configuration format. Just keys and values. |
| Portability | Supported by almost every language framework (Node.js dotenv, Python-dotenv, Ruby dotenv). |
How to create env files
- Text Editor: Create a file named just `.env` (no filename before the dot).
- CLI: `cp .env.example .env`.
How to convert env files
- FileXhost: Upload to share example configurations (`.env.example`).
Advantages & disadvantages
Advantages
- Keeps secrets out of your code
- Easy to change configuration without redeploying code
- Standard practice for modern cloud-native apps
Disadvantages
- Easy to accidentally commit to Git if not careful
- No standard for complex data types (only strings)
- Syntax varies slightly between different parsers (e.g., handling of quotes/spaces)
Tools & software
Libraries
dotenv (Node.js, Ruby), python-dotenv (Python), godotenv (Go)
DevOps
Docker, Kubernetes, Vercel, Netlify (all support env vars)
Frequently asked questions
Should I commit my .env file?
NO! Never commit your `.env` file to Git. It often contains secrets. Commit a `.env.example` instead with dummy values.
Why is the file hidden?
Files starting with a dot (`.`) are treated as hidden files by Unix-based systems (macOS, Linux) to prevent clutter.
How do I read it in code?
Use a library like `dotenv` to load the variables into your process (e.g., `process.env.KEY` in Node.js).
Technical specs
- File type
- Code
- Extension
- .env
- MIME type
- text/plain
- Compression
- Uncompressed
- Max file size on FileXhost
- Typically very small (< 4KB). Up to 25 MB per file on free plans.
Share .env files instantly
Upload your .env file to FileXhost to get a clean, shareable URL in seconds. View the file in a modern browser, protect access with optional settings, and let others download it without any confusing ads or cluttered file pages.
Upload .env file