dotenv Linter — Validate .env Files
Catch .env mistakes before they break your deploy
Runs 100% in your browser — nothing is ever uploaded.
What is dotenv Linter?
Paste a .env file and get an instant lint report: duplicate keys (the silent config killer), invalid or lowercase names, whitespace around =, unbalanced quotes, empty values and lines that aren't KEY=value at all — each issue with its exact line number.
How to use dotenv Linter
- Paste your .env file into the input box or click “Load sample” to try it.
- Adjust the options in the toolbar if needed (delimiter, table name, format …).
- Click the convert button — the lint report appears instantly in the output pane.
- Copy the result with one click or download it as a file.
ConvertLab FAQ
Is the dotenv linter free?
Yes — 100% free, no signup, no limits, no watermarks. Use it as often as you like.
Why do duplicate keys matter?
Most dotenv loaders silently keep either the first or the last occurrence — which one differs per library. A duplicate key is therefore a config bug waiting to happen; the linter flags every one with both line numbers.
Is my data uploaded to a server?
No. The conversion runs entirely in your browser with JavaScript — your data never leaves your device, which makes the tool safe even for confidential files.
Are these converters free?
Yes — every ConvertLab tool is 100% free with no signup, no limits and no ad walls.
Is my data uploaded anywhere?
No. All conversions (JSON, CSV, XML, YAML, INI, .env) run entirely in your browser. Nothing ever leaves your device.
Do these tools work offline?
Yes — once the page is loaded, every converter works without an internet connection.