Password Strength Checker — Test Your Password
Free password strength checker: test password strength instantly — 0–4 score, crack-time estimate, and improvement tips. Runs 100% in your browser.
Password Strength Checker
Answer the checklist below for an instant 0–100 score — a guide to help you improve, not a guarantee.
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What is Password strength checker?
Password Strength Checker — Free password strength checker: test password strength instantly — 0–4 score, crack-time estimate, and improvement tips. Runs 100% in your browser.
Scoring is done by zxcvbn-ts, the open-source TypeScript port of Dropbox's zxcvbn password-strength estimator (vendored). It matches your password against an English dictionary of common words, names, and Wikipedia terms plus pattern detectors (repeats, character sequences, l33t substitutions), estimates how many guesses an attacker would need, and converts that into a 0–4 score and a crack-time display. The crack time shown is the offline slow-hash scenario (10,000 guesses/second, like bcrypt) — real attacks vary widely, so treat every score as an estimate, not a guarantee. Everything runs client-side; your password never leaves your browser.
Why use this password strength checker?
Built for password strength checker
Free password strength checker: test password strength instantly — 0–4 score, crack-time estimate, and improvement tips. Runs 100% in your browser.
Transparent & honest
Scores are heuristic estimates of guessability, not guarantees — a high score does not make a password uncrackable.
Private by design
Everything runs in your browser. Your inputs never leave your device.
Works everywhere
Fully responsive — perfect on desktop, tablet, and mobile. No app needed.
Regularly updated
Regularly maintained and reviewed to ensure accuracy.
Free forever
No accounts, no limits, no watermarks. Use Password Strength Checker as much as you need.
How to use Password Strength Checker
- 1Type a password into the "Password to test" field. Your password is never sent anywhere — scoring happens in your browser.
- 2Run the tool to get a 0–4 strength score, a plain-language label (Very weak to Very strong), and an estimated crack time.
- 3Read the improvement suggestions — add length and unpredictability to raise your score.
- 4Try variations of your password and re-run until you reach Strong or Very strong.
- 5Use a unique strong password for every account; consider a password manager instead of reusing one.
What can you do with Password Strength Checker?
- Check password strength without sending password anywhere — Free password strength checker: test password strength instantly — 0–4 score, crack-time estimate, and improvement tips.
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- Safe to type real password into checker — Free password strength checker: test password strength instantly — 0–4 score, crack-time estimate, and improvement tips.
Good to know
- Scores are heuristic estimates of guessability, not guarantees — a high score does not make a password uncrackable.
- The crack time shown is one scenario (offline attack at 10,000 guesses/second); online throttled attacks are far slower and fast-hash offline attacks far quicker.
- Only the English dictionary pack is bundled and no keyboard-adjacency graphs, so non-English common words and keyboard walks (e.g. "qwerty") may score slightly higher than they deserve; the meter also cannot know if your password was exposed in a breach.
- Passwords longer than 512 characters are truncated to 512 before scoring.
How it works
Scoring is done by zxcvbn-ts, the open-source TypeScript port of Dropbox's zxcvbn password-strength estimator (vendored). It matches your password against an English dictionary of common words, names, and Wikipedia terms plus pattern detectors (repeats, character sequences, l33t substitutions), estimates how many guesses an attacker would need, and converts that into a 0–4 score and a crack-time display. The crack time shown is the offline slow-hash scenario (10,000 guesses/second, like bcrypt) — real attacks vary widely, so treat every score as an estimate, not a guarantee. Everything runs client-side; your password never leaves your browser.
Examples
Status: ok — score 0 (Very weak), crack time "less than a second".
Status: ok — score 4 (Very strong), crack time "centuries".
Status: ok — score 4 (Strong), with suggestions if any pattern is detected.
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