.env Validator
Validate .env syntax, detect duplicate keys, and view all variables in a table.
Safe for API keys — all processing is browser-local.
About
A free tool to validate and analyze .env files for syntax errors, duplicate keys, and variable definitions — all in your browser. Supports Node.js dotenv conventions and Docker Compose env_file format.
Sensitive values like API keys are automatically masked in the variable table. No data ever leaves your device.
How to Use
Paste .env Content
Paste your .env file content into the left text area.
Real-Time Analysis
Syntax errors, duplicate keys, and variable list update instantly.
Fix Errors
Review flagged lines and fix them in your .env file.
Glossary
- .env File
- A text file defining environment variables in KEY=VALUE format. Typically git-ignored and not committed to repositories.
- Environment Variable
- OS-level variables that applications read at runtime for configuration (DB credentials, API keys, feature flags, etc.).
- 12-Factor App
- A methodology for building SaaS apps. Factor III states configuration should be stored in environment variables.
- dotenv
- A Node.js library that reads a .env file and injects the variables into process.env.
- Secret Management
- Best practices for securing API keys and credentials. Production environments should use AWS Secrets Manager, Vault, etc.
- Comment Line
- In .env files, lines starting with # are comments and are ignored by the parser.
FAQ
- Q.Est-il sécuritaire de coller des clés API ?
- Oui. Tous les traitements s'exécutent localement dans votre navigateur. Aucune donnée n'est jamais transmise à un navigateur.
- Q.Les valeurs citées sont-elles prises en charge ?
- Oui. Les valeurs entre guillemets simples et doubles (par exemple SECRET="ma valeur") sont analysées correctement.
- Q.Est-ce que ça marche pour .env.local ou .env.production ?
- Oui. Tout fichier suivant le même format KEY=VALUE est pris en charge.
- Q.Les valeurs multilignes sont-elles prises en charge ?
- Non. Cet outil valide les entrées KEY=VALUE sur une seule ligne. Les valeurs hérdociennes multilignes ne sont pas prises en charge.
Cas d'utilisation
🖥️ Node.js Development
Debug dotenv syntax before running your app.
🐳 Docker Compose
Validate env_file referenced in docker-compose.yml.
🔐 Pre-Deploy Check
Confirm all required variables are defined before deployment.
👥 Team Sharing
Clean up .env.example before sharing with the team.