.env Validator
Paste an env file and instantly find duplicate keys, invalid ports, malformed database URLs, broken flags, and other common configuration mistakes.
Frequently Asked Questions
What is a .env file validator?
It parses the contents of a .env file and checks every KEY=VALUE pair for common mistakes: duplicate keys, invalid ports, malformed database URLs, broken boolean flags, missing values, and weak secrets.
What does the .env validator check?
It flags duplicate keys, validates ports (must be integers 1-65535), checks database URLs (postgres, mysql, mongodb, redis, mssql, sqlite and more), validates URL/URI/endpoint keys, boolean flags, numeric settings, key naming conventions, empty values, and weak or placeholder secrets.
Does the tool store or transmit my environment variables?
No. The .env validator runs entirely in your browser — the file contents are never uploaded, stored, or sent to any server. Values are also masked by default for privacy.
How are duplicate keys flagged?
Every occurrence of a key after the first is marked with a Duplicate badge. In most runtimes the last definition wins, so duplicates are a common source of bugs.
Is this tool free?
Yes, ToolDock's .env validator is completely free, requires no signup, and runs entirely in your browser.