Hibp Sha1 Prefix

K-anonymity HIBP password check: hash locally, send only the SHA-1 prefix, see if the suffix is listed.

About this tool

The password is SHA-1 hashed locally. The tool sends only the first five hash characters to the Pwned Passwords range API, then compares the returned suffixes in the browser. A result is useful evidence that a password must not be used; a result of zero does not establish that it is strong.