Password Strength Checker
See how fast a password could be cracked, with practical tips, on your device.
How to use Password Strength Checker
- Type the password. It is analysed as you type, on your device.
- Read the score, estimated crack times and specific weaknesses.
- Optionally check whether it appears in known data breaches.
How it works
Strength is estimated with zxcvbn, an open-source estimator originally from Dropbox (here the maintained zxcvbn-ts version). Instead of only counting character types, it looks for what attackers actually try first: common passwords, dictionary words, names, dates, keyboard patterns like "qwerty" and substitutions like "p@ssw0rd". The crack times show an online attack (throttled login) and an offline attack against a fast hash.
The optional breach check uses Have I Been Pwned’s k-anonymity API: your browser hashes the password with SHA-1 and sends only the first 5 characters of the hash; the service returns all matching suffixes and the comparison happens on your device. The password itself is never sent. It is off by default.
Frequently asked questions
Is it safe to type my real password here?
Analysis happens entirely in your browser and nothing is stored or sent, unless you turn on the breach check, which sends only a 5-character hash prefix. Still, prefer testing passwords similar to yours rather than the exact ones.
Why is "P@ssw0rd2026!" rated weak?
It is a dictionary word with predictable substitutions, a year and a symbol at the end: exactly the patterns cracking tools try first.
What score should I aim for?
A score of 4 (very strong) for important accounts. Better still, use a password manager with long random passwords.
What does "found in breaches" mean?
The exact password appears in leaked password lists, so attackers will try it early. Do not use it anywhere.
Limitations
- Crack times are estimates under stated assumptions, not guarantees.
- Dictionaries are English-focused; non-English words may be under-detected.
Last reviewed November 9, 2026. How we build and test tools.