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.

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.

Security & Cryptography

Password Strength Checker

Check password strength with entropy and estimated crack time.

Free browser toolRuns in your browserNo sign-up

Password

StrengthEmpty

Length

Character pool

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.

100% private - runs entirely in your browser.

Your input, keys and passwords are never uploaded. Want proof? Load this page, then turn off your internet - the tool still works. For an exact check, open your browser's DevTools Network tab and confirm no data is sent when you use it.

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: password1

Output: Very weak

Common words and short length make it easy to guess.

Strong password

Input: a 16-character mix of cases, digits and symbols

Output: Very strong

Length 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.

Security GuidesHow to Create a Strong Password You Can Actually ManageRead guide

Open a related tool to prepare your files or refine the finished result.