Validator

Check credit card or other numbers via the Luhn algorithm – including card type detection. Runs locally in the browser.

Validate an IBAN – via the checksum per ISO 7064 (modulo 97). Runs entirely in the browser, nothing is sent.

Check whether a password appears in known data breaches – via the Have I Been Pwned API with k-anonymity. The password is never sent.

Test regular expressions online – with flags, a live match list and groups. Uses the JavaScript regex engine, runs in the browser.

Validate, format and minify JSON online – with error display. Runs entirely in the browser, no data is sent.

Validate and format YAML online – syntax checking with error details and prettify. Runs entirely in the browser, no data is sent.