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.env File Diff, Validator & .env.example Generator

Compare two .env files by key, spot missing variables or syntax errors, and generate a redacted .env.example — 100% locally.

Runs 100% in your browser Free, no sign-up Updated

Comparison & Template Export

Variable Key Status Left Value Right Value
Paste two .env files above to compare keys and values.
by ProWebLook

How to use the .env File Diff & Validator

  1. Paste your base environment file (such as .env.example or staging) on the left and the target file (such as .env.production or .env.local) on the right.
  2. Toggle “Mask secret values” when screen-sharing or reviewing production credentials so only key names and match status are shown.
  3. Inspect the structural report for Missing Keys, Extra Keys, Changed Values, Empty Variables, and Duplicate/Syntax warnings.
  4. Switch to the “.env.example Generator” tab to export a clean template with API keys, passwords, and tokens automatically redacted.

Why compare and validate .env files locally?

Almost every modern twelve-factor application — across Node.js, Laravel, CodeIgniter, Python, Go, Rust, and Docker Compose — relies on environment variables loaded from .env files. One of the most frequent causes of production outages after a deployment is configuration drift: a developer adds a new API key or feature flag to their local .env file, forgets to document it in .env.example or the production secrets manager, and the app crashes on startup or silently falls back to broken defaults.

Because .env files hold your highest-privilege credentials (database passwords, Stripe secret keys, JWT signing keys, AWS tokens), you should never paste them into server-side diff utilities. This .env File Diff, Validator & .env.example Generator executes 100% locally in your browser with zero network calls.

What this .env inspector detects

  • Missing & extra keys across environments: Instantly highlights variables present in Left (e.g. .env.local) that are missing from Right (e.g. .env.production or .env.example), and vice versa.
  • Empty & modified values: Flags variables that are defined in one file but left blank (KEY=) in the other, or whose values differ between staging and production.
  • Duplicate key definitions: Detects when the same variable is declared twice inside the same .env file — a subtle bug where the bottom declaration silently overwrites the first.
  • Syntax & quoting pitfalls: Catches unquoted values containing spaces, invalid variable names, stray export prefixes, and inline # comments that aren’t separated by whitespace.

Automatic .env.example secret scrubbing

Clicking Generate .env.example builds a clean, safe-to-commit template from your environment file. Non-sensitive structural defaults (such as PORT=8080, NODE_ENV=development, LOG_LEVEL=info, or boolean flags like ENABLE_CACHE=true) are preserved or clearly labeled, while keys matching sensitive patterns (SECRET, PASSWORD, TOKEN, KEY, DSN, PRIVATE, or high-entropy bearer strings) are replaced with safe placeholders such as your_api_key_here.

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Frequently asked questions

Is it safe to paste production .env files here?
Yes. Unlike general text tools that send inputs to a backend, this tool runs 100% locally in your browser. Furthermore, the workspace is isolated from analytics capture, and you can enable “Mask secret values” so credentials are never even rendered in plain text on your screen.
Why use a dedicated .env diff instead of a standard text diff?
In a standard line-by-line diff, reordering sections, adding comments, or changing blank lines creates noisy false positives. This structural .env comparator parses KEY=VALUE assignments, ignores comment/key ordering, and immediately highlights keys that exist in .env.example but are missing in .env.production — the #1 cause of deployment crashes.
What syntax issues does the .env linter catch?
It detects duplicate variable keys within the same file (where the second assignment silently overwrites the first), unclosed single or double quotes, accidental spaces around the = sign (e.g. KEY = val), invalid variable identifiers, and empty assignments.
How does the .env.example sanitizer decide which values to redact?
Keys matching sensitive patterns (such as SECRET, KEY, TOKEN, PASSWORD, PASS, PRIVATE, DSN, DATABASE_URL, or high-entropy strings) are replaced with descriptive placeholders like your_api_key_here, while safe configuration defaults (PORT=3000, NODE_ENV=development, booleans) can be preserved.
Are export prefixes and quoted multiline values supported?
Yes. Lines prefixed with export , inline # comments outside quotes, single/double/backtick quotes, and variable interpolation syntax (${VAR}) are parsed accurately.

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