Security & Cryptography
Password Strength Checker
Check password strength with entropy and estimated crack time.
Free foreverRuns in your browserNo sign-up
StrengthEmpty
Length
0
Character pool
0
Entropy
0 bits
Crack time
-
- Enter a password to check.
The crack time is a rough estimate assuming ten billion guesses per second. Everything runs in your browser and your password is never sent anywhere.
About the Password Strength Checker
Check how strong a password is by looking at its length, character variety and estimated time to crack.
It reports the entropy in bits, the character pool size, a strength rating and practical suggestions to improve it.
Your password is analysed entirely in your browser and is never sent anywhere.
Key features
- Entropy in bits and character pool size
- Strength rating with a visual meter
- Estimated crack time
- Actionable improvement tips
How to use
- 1Type or paste a password to test.
- 2Read the strength rating, entropy and crack time.
- 3Follow the suggestions to make it stronger.
Examples
Weak password
Input:
password1Output:
Very weakCommon words and short length make it easy to guess.
Strong password
Input:
a 16-character mix of cases, digits and symbolsOutput:
Very strongLength plus variety pushes the entropy high.
Frequently asked questions
- How is the crack time estimated?
- It assumes a fast offline attacker making about ten billion guesses per second, then divides the size of the search space by that rate.
- What is entropy?
- Entropy measures unpredictability in bits. More length and more character variety mean higher entropy and a stronger password.
- Is my password uploaded?
- No. The check runs entirely in your browser and nothing is stored or sent.