Password Entropy Calculator
Free online password entropy calculator that runs entirely in your browser.
How the Password Entropy Calculator works
The Password Entropy Calculator works on Password length, Character pool size and shows the result as you type. The same input always gives the same answer — refresh the page and you will see exactly the same figure.
Formula used
Password Entropy Calculator is computed by the formula below, using the inputs you provide.
Inputs used: Password length, Character pool size.
Worked example
Take the default example — password length of 16:
- Entropy: 98
- Brute-forceable in reasonable time: false
- combinations: 2^100
Frequently asked questions
- Is the Password Entropy Calculator free?
- Yes. There is no signup, no usage limit and no watermark — the calculator runs entirely in your browser.
- Does the Password Entropy Calculator store or send my data?
- No. Every calculation happens locally in the page, so the numbers you type are never uploaded or logged.
- Does it work on a phone and offline?
- Yes — the page is a single lightweight file that adapts to any screen size. Once it has loaded it keeps working without a network connection.
- What inputs does the Password Entropy Calculator need?
- Password length, Character pool size. Change any of them and the result updates instantly.