🛡️ Password Strength Checker
Check how strong a password really is. Everything runs locally in your browser — your password is never stored or sent anywhere.
What makes a strong password?
Length matters most: every extra character multiplies the number of guesses an attacker needs. A long passphrase of random words beats a short "complex" password.
Entropy here is estimated as length × log₂(charset size), with penalties for common words, repeated characters, and sequential runs. It is an approximation, not a guarantee.
Check how strong a password really is. The tool analyses its length and character variety, calculates entropy in bits, and estimates how long it would take to crack at several realistic attack speeds — and the password never leaves the page.
Frequently asked questions
Is it safe to type my real password here?
The check runs entirely in your browser — the password is never sent, stored or logged anywhere. That said, a sensible habit is to test a similar pattern rather than an exact password you already use for an important account.
What does password entropy mean?
Entropy measures unpredictability in bits: it depends on the size of the character set you draw from and the length of the password. Each extra bit doubles the number of guesses an attacker needs, which is why length increases strength faster than swapping letters for symbols.
How is the time-to-crack estimated?
It divides the number of possible combinations by several assumed guessing rates, from online attacks (slow, rate-limited) to offline attacks with dedicated hardware (billions of guesses per second). Real times vary with how the password is stored, so treat the figures as rough comparisons rather than guarantees.
What makes a strong password?
Length matters most: a long passphrase of random words beats a short complex string. Aim for 14+ characters, avoid dictionary words with predictable substitutions, and never reuse a password across accounts — a password manager makes all of this easy.