Password Strength / Generator
Measure password strength (entropy and estimated crack time) and generate strong passwords. Everything runs in your browser; your input is never sent.
Everything runs in your browser. Your input is never sent to a server.
Check strength
Generate a strong password
How to use
- 1
Type a password above to see its entropy (bits), strength, and estimated crack time.
- 2
Use the generator below to create and copy a strong password by length and character set.
- 3
For important accounts, use a long generated password + a password manager + multi-factor auth.
Why it matters
Strength comes down to length and randomness (entropy). Real words and substitutions (@ for a, etc.) are easy to guess and weaker than they look. The practical optimum: a unique long random string per site, and the only thing you memorize is your manager's master password.
FAQ
QIs my password sent anywhere?
A
No. Both the strength calculation and generation run entirely in your browser; nothing is sent to a server.
QHow accurate is the 'crack time'?
A
It varies hugely with attacker hardware and hashing, so it's only a guide. We assume a fast offline brute force (~10 billion guesses/sec). Entropy (bits) is the more objective metric.