.env File Validator & Linter
Paste your .env file and instantly catch duplicate keys, empty values, unquoted spaces, and secrets that should never be stored in plaintext, all checked locally in your browser.
Results
How to validate a .env file
From messy .env to clean and secure in four steps.
- 1
Paste your .env file
Drop your environment file into the validator. It works with .env, .env.local, or any raw KEY=VALUE block.
- 2
Review the results
See every issue flagged with a line number, duplicates and case-only collisions, empty values, unquoted strings with spaces, and secrets that should be encrypted.
- 3
Fix the problems
Remove duplicates, quote values with spaces, drop empty keys, and decide which secrets to move out of the file.
- 4
Secure secrets with Envless
Store flagged credentials end-to-end encrypted in Envless, commit a .env.example template instead, and give your team safe access without plaintext exposure.
Why use the Envless .env validator?
A fast, private linter from a team that manages environment variables for a living.
Line-by-line validation
Detects duplicate keys, including two keys that differ only in case, plus empty values, missing quotes around values with spaces, non-standard key names, keys that are not UPPER_SNAKE_CASE, and spaces around the = sign, with a line number for every issue.
100% client-side scanning
Your .env file never leaves your browser. No uploads, no logging, no network calls, parsing and validation happen entirely on your device.
Secrets detection
Flags keys that look like secrets (SECRET, KEY, TOKEN, PASSWORD, API_KEY) so you never accidentally commit plaintext credentials to version control.
Built for secure teams
Once the issues are fixed, store and share your variables end-to-end encrypted with Envless instead of committing .env to git or pasting it into chat.
.env validator FAQ
Everything you need to know about linting and securing your .env files.
No. The validator runs entirely in your browser. Your .env file never leaves your device, there are no uploads, no logging, and no network requests.
Duplicate keys, two keys that differ only in case, empty values, values with spaces that are not quoted, spaces around the = sign, non-standard key names, keys that are not UPPER_SNAKE_CASE, and keys that look like secrets (SECRET, KEY, TOKEN, PASSWORD, API_KEY, and similar).
Most .env parsers use the last value when a key appears twice. Duplicates are usually a mistake and can silently override secrets or cause unexpected behavior. The same goes for two keys that differ only in case, which most tooling treats as one key.
The validator treats them as a collision and flags the second one. A shell keeps them apart, but almost nothing downstream does, and Envless itself requires a variable name to be unique inside an environment without regard to case. Envless stores the casing you give a key and never rewrites it, so pick one spelling per key and stay with it.
No. UPPER_SNAKE_CASE is a widespread convention, so the validator points out keys that break it, but Envless accepts any name matching ^[A-Za-z_][A-Za-z0-9_]* of 1 to 100 characters and stores it with exactly the casing you typed.
Move them out of the .env file. Store credentials end-to-end encrypted with Envless so your team can access them safely, and commit a .env.example with empty values instead.
Neither. The validator is completely free with no rate limits and no sign-up required. Validate as many .env files as you need.
Yes. The validator works with any .env file regardless of framework, Next.js, Django, Rails, Go, or anything else that uses KEY=VALUE environment files.
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Ship secrets, not chaos.
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