Password Strength Checker
Estimate password strength from length and character variety, with tips to improve it.
Strength: —
- Estimated entropy
- 0 bits
- Length
- 0
Ways to improve:
How strong is your password?
The Password Strength Checker estimates how resistant a password is to guessing. It measures two things: the length of the password and the variety of character types it uses — lowercase, uppercase, digits and symbols. From these it estimates the entropy in bits and maps it to a rating from Very Weak to Very Strong.
Why entropy matters
Entropy measures how many guesses an attacker would need on average. Each extra character and each extra character type multiplies the number of possibilities, so entropy rises quickly with length. The check runs entirely in your browser — your password is never sent anywhere or stored.
How to use the Password Strength Checker
- Type a password. Enter or paste the password you want to test.
- Read the rating. The coloured bar and label show Very Weak through Very Strong.
- Check the entropy. See the estimated bits of entropy alongside the length.
- Follow the tips. Apply the listed suggestions to make the password stronger.
Frequently asked questions
Is my password sent anywhere?
No. The check runs entirely in your browser; nothing is uploaded, logged or stored.
How is the rating calculated?
From estimated entropy: the password length multiplied by the bits per character implied by the character types it uses.
Does it check breached-password lists?
No. It measures structural strength only, so still avoid common words and reused passwords.
What rating should I aim for?
Strong or Very Strong for important accounts, which usually means 16 or more characters with mixed types.