Password strength auditor — entropy, crack time, warnings
Type a password and see its strength: estimated entropy, a realistic offline crack time, and specific warnings. It checks entirely in your browser (0 uploads, works offline) — the only safe way to test a real password.
How to use it
- Type or paste the password.
- Read the strength, entropy and crack-time estimate.
- Act on the warnings and suggestions.
FAQ
How do I check my password strength safely for free?
Type it here. This page estimates entropy from length and character variety, penalises common passwords, sequences and repeats, and shows a crack-time estimate — entirely on your device with no upload, which is exactly why it is safe to test a real password.
Is my password sent anywhere?
No. It is analysed entirely in your browser and nothing is transmitted or stored, which you can verify by turning off your Wi-Fi. A password strength checker that uploaded your password would be dangerous by design.
How is crack time estimated?
It assumes a fast offline attacker guessing about ten billion times a second and reports how long the full keyspace would take at that rate. It is a guide, not a guarantee.
What makes a password strong?
Length first, then variety. A long passphrase of several unrelated words beats a short string of symbols, and avoiding common words and sequences matters as much as adding character types.
Limits
Estimates strength from structure; it cannot know whether a password has already appeared in a breach.
Related
The AES tool encrypts data with a password; the secret scanner finds keys in code.
Bookmark this page (Ctrl+D, or ⌘D on Mac) or install the app — it works offline the next time you need it.