Password Strength Checker
Estimate password strength without sending it anywhere.
Use the Password Strength Checker tool
What this password strength checker does
Password strength is mostly about how many guesses an attacker needs. This checker estimates the search space from the characters you use, adjusts for obvious patterns, and converts the result into an offline cracking estimate.
The password is analysed in memory with plain JavaScript. There is no network request, no logging and no storage, which is the only sensible way to handle a real credential.
Why use it
- See how much length actually adds compared with swapping letters for symbols.
- Understand why a short complex password can be weaker than a long passphrase.
- Spot banned patterns such as keyboard runs, dates and repeated characters.
How to use it
- 1Type or paste the password you want to evaluate.
- 2Read the entropy score, the estimated search space and the warnings.
- 3Lengthen the password first; add symbols and mixed case only after length is adequate.
Worked examples
Short and complex
Input
P@ssw0rd!
Output
Common substitutions are recognised, so the effective score stays low despite the symbols.
Long passphrase
Input
four unrelated words plus a number
Output
A much larger search space and a crack time measured in years rather than hours.
Common mistakes
- Assuming a symbol requirement makes a password safe — length dominates.
- Reusing one strong password across sites, where a single breach exposes all of them.
- Testing a live password on an unknown website; use a local checker like this one instead.
Frequently asked questions
Is it safe to type my real password here?
The value never leaves the page, but the safest habit is to test a password that resembles your pattern rather than the exact credential you use.
How is crack time calculated?
It divides the estimated search space by an offline guessing rate and assumes the attacker has a fast hash-cracking rig. It is an order-of-magnitude guide, not a promise.
What length should I aim for?
Twelve characters is a floor, sixteen or more is comfortable, and a four-word passphrase is usually both longer and easier to remember.
Do you store what I type?
No. There is no server call, no analytics on the field and no local storage write.
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