.env File Validator (Strict)

Paste a .env file, get a per-line validation report. Catches duplicate keys (a common source of mysterious bugs), values with characters that need quoting, comments not on their own line, malformed key names, and other issues that different .env loaders handle differently.

How to use the .env File Validator (Strict)

Paste a .env file. The validator reports each issue with its line number and severity. Most loaders (dotenv-js, python-dotenv, godotenv, Ruby dotenv) handle .env files slightly differently — this validator targets the strictest common subset so your file works everywhere.