Password Strength Checker
Check how strong a password really is — entropy, estimated crack time and the weak patterns attackers look for. Checked privately in your browser.
How to use
- 1Type a password (it never leaves your device).
- 2See the strength rating, crack-time estimates and what to improve.
How it's calculated
Entropy starts at length × log₂(character pool), then points are removed for common passwords, dictionary words (including @-for-a swaps), keyboard sequences, repeats and years. Crack time assumes the attacker searches half the space on average.
Frequently asked questions
Is it safe to type my password here?
The check runs entirely in your browser and nothing is sent or stored. Still, it's good practice to test a similar password rather than your real one.
What makes a password strong?
Length and randomness. A random 16-character password or a 6-word random passphrase is far stronger than a short one with symbols swapped in.
Why do the two crack times differ so much?
Online attacks are slowed by login rate limits (~10 guesses a second). If a site's password database leaks with a fast hash, attackers can try 10 billion guesses a second offline.