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ENV Diff Checker

Compare two .env files side by side. Instantly see added, removed, and changed variables between environments.

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Added1
NEW_KEY
•••••
Removed1
OLD_KEY
•••••
Changed3
DATABASE_URL
po••••••••••••••••••••ev → po•••••••••••••••••••••••••••pp
PORT
•••• → •••
DEBUG
•••• → •••••

What it does

  • ▸Side-by-side diff of two .env files
  • ▸Groups added, removed, and changed keys
  • ▸Masks sensitive values in the output
  • ▸Copy the diff as a shareable report
  • ▸100% client-side

Privacy

Runs 100% in your browser. Your .env never touches our servers.

client-side only

Usage examples

Case 1 · Value changed
// A (local)
DB_URL=postgres://localhost/dev
PORT=3000

// B (prod)
DB_URL=postgres://prod.example.com/app
PORT=443
~ DB_URL
  - postgres://localhost/dev
  + postgres://prod.example.com/app
~ PORT
  - 3000
  + 443
Case 2 · Added / removed keys
// A
API_KEY=old
OLD_FLAG=1

// B
API_KEY=old
NEW_FEATURE=true
+ NEW_FEATURE=true
- OLD_FLAG=1
= API_KEY  (unchanged)
Case 3 · Fully synchronized
// A
KEY=value

// B
KEY=value
✓ No drift. Files are identical.

When to use this tool

  • →Pre-release check between staging and production .env files
  • →Onboarding a teammate whose .env.local has drifted from yours
  • →Debugging why a deploy works locally but fails in CI
  • →Reviewing a PR that adds or removes environment variables
  • →Migrating from one host (Heroku, Fly, Railway) to another

Common mistakes

  • ⚠Diffing .env files that were generated by different frameworks — naming conventions differ
  • ⚠Assuming "missing in B" is a bug: sometimes a key was intentionally deprecated
  • ⚠Sharing an unmasked diff in a ticket — use the mask toggle before copying
  • ⚠Ignoring "changed" rows because the diff looks noisy — those are usually the real bugs

ENV Diff Checker — compare two .env files

When .env.local and .env.production drift, deploys break in subtle ways. Paste both files and this env diff tool shows you exactly which keys were added, removed, or changed — with values masked so you can safely share the report with a teammate.

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Learn more

guide · 9 min
How to fix .env file errors (complete troubleshooting)
The 12 most common .env file errors — missing values, duplicate keys, bad quotes, encoding issues, case sensitivity — with exact fixes for each.
guide · 8 min
10 .env best practices every team should follow
Battle-tested rules for .env files: what to commit, what to rotate, how to structure secrets across dev, staging, and production, and the common mistakes that cause outages.
coming soon

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