~/tools/entropy
Password entropy estimator
Estimate a password's strength from its character set and length. Everything runs locally — the password is never sent or stored.
Strength
- Entropy
- Length
- Charset
- Crack time
Entropy is estimated as length × log2(pool size),
where pool size is the number of distinct character classes used. The crack-time figure assumes
1010 guesses per second against a fast offline attack
on a well-chosen hash, and shows the average (half the keyspace).
This is a first-order model. It does not catch dictionary words, keyboard walks, l33t substitutions, or reuse — a tool like zxcvbn does that far better. A long, random, unique passphrase from a password manager beats anything you can type from memory.