Type or paste a password below to see a rough strength estimate. Everything runs in your browser — your password is never sent to our server or stored anywhere, not even temporarily.
Checked locally in your browser — the password you type here is never sent to our server or stored anywhere, not even temporarily.
Computed entirely in your browser — nothing you enter here is sent to our server.
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How This Estimate Works
This tool estimates entropy (a measure of unpredictability, in bits) from the character types actually used in your password and its length — the standard formula is length × log2(pool size). It then applies simple, disclosed penalties for heavy repetition and for simple sequences like “abcdefg” or “12345678”, both of which have high raw entropy by that formula but are trivially easy to guess.
What this tool does NOT do: it does not check your password against known data-breach lists, does not check for dictionary words, and is not a substitute for a full password-strength library. Treat the result as a rough guide, not a guarantee.
FAQ
Is my password uploaded anywhere?
No. The check happens entirely in your browser using JavaScript. What you type is never sent to our server, logged, or stored.
Why does a long password of repeated characters score low?
Because it’s easy to guess despite its length — this tool specifically penalizes heavy repetition (e.g. “aaaaaaaa”) and simple sequences, rather than scoring purely on length and character variety.
Does this check against known data breaches?
No — that would require sending your password to an external service, which this tool deliberately never does. It only estimates entropy locally.