.env File Validator
Environment variable files (.env) are commonly used in modern application development, but syntax errors, duplicate definitions, and sensitive information leaks can cause application errors or security vulnerabilities. This tool helps you quickly validate .env file format and security, with all checks running locally in your browser.
Common .env File Issues
- Missing equals sign: No = separator between key and value
- Empty key name: No variable name before the equals sign
- Duplicate keys: Same variable defined multiple times
- Sensitive information exposure: Passwords and keys stored unencrypted
- Non-standard key naming: Should use uppercase letters and underscores
- Unmatched quotes: String values with unclosed quotes
.env File Best Practices
- Never commit .env files to version control
- Provide .env.example as a template
- Use uppercase letters and underscores for variable names
- Use different .env files for different environments
- Regularly rotate API keys and passwords
What is a .env file?
A .env file is a plain text file used to store environment variables, typically for configuring application runtime parameters like database connections, API keys, etc. It is recommended by the 12-Factor App methodology.
Why validate .env files?
Syntax errors, duplicate keys, and sensitive information leaks in .env files can cause application errors or security risks. A validator automatically detects these issues.
What are .env file format rules?
One key-value pair per line in KEY=VALUE format. Lines starting with # are comments. Blank lines are ignored. Key names should use uppercase letters and underscores. Values can be wrapped in single or double quotes.
Is my data uploaded to a server?
No. All validation runs locally in your browser. No data is uploaded to any server.