Pure Frontend · .env File Diff · Highlight Added/Removed/Modified · Merge
Zero Dependencies · Works OfflineWhat Does the Env Diff Tool Do?
The Env Diff Tool is a pure frontend tool for comparing two .env files. It highlights added (green), removed (red), and modified (yellow) variables, and provides multiple merge strategies to generate a final environment variable file. Ideal for development teams syncing environment configurations across dev/staging/production environments. All data is processed locally in your browser.
Core Features
- Diff Highlighting: Added in green, removed in red, modified in yellow — clear at a glance
- Statistics Overview: Count of added/removed/modified/unchanged variables
- Merge Strategies: A-wins, B-wins, or B-new-only merge modes
- Drag & Drop: Drag .env files directly into input areas
- Comment Handling: Correctly processes # comment lines and empty lines
How to Use
Step 1: Paste base .env content in the left input, comparison .env in the right, or drag files.
Step 2: Click "Compare Diff" or Ctrl+Enter to see the diff table and statistics.
Step 3: Choose a merge strategy (A-wins/B-wins/B-new-only) to see the merged result.
Step 4: Copy or download the merged .env file. Ctrl+Shift+C for quick copy.
Use Cases
Multi-Environment Sync
Compare dev, staging, and production .env files to ensure critical configs are consistent across environments.
Team Onboarding
New team members can compare their local .env against the team template to quickly identify missing configs.
CI/CD Review
Review environment variable changes before deployment to confirm no critical configs were accidentally removed.
Config Migration
When migrating between systems, compare env diffs to ensure all necessary configurations have been transferred.
Extended Knowledge
The .env file is recommended by the 12-Factor App methodology for environment variable management. Format: KEY=VALUE, one per line. Lines starting with # are comments. Values can be wrapped in single or double quotes, supporting multiline values. Best practice: commit .env.example (without real values) to version control, add .env (with real values) to .gitignore. Docker Compose loads .env files via the env_file directive.
FAQ
Which env formats are supported?
Standard .env format (KEY=VALUE), comment lines (# prefix), empty lines, quoted values, and Docker Compose environment block format.
Will my env data be uploaded?
No. All comparison and merging happens in your browser. Environment variable content never leaves your device.
How are differences displayed?
Added variables in green, removed in red, modified in yellow, with old and new values shown.
Can I generate a merged result?
Yes. Choose A-wins, B-wins, or B-new-only merge strategies to generate the final .env file.
Can I drag and drop .env files?
Yes. Drag .env files directly into the corresponding input areas.