// tool reference · Platform & Learning

Password Entropy Analyzer Free

パスワードの強度、エントロピー、解読にかかる時間をローカルで推定します。

What it does

Calculates actual entropy in bits and estimates crack time against realistic attack rates — rather than the meaningless "strong!" meter most sites show.

When to use it

Setting a password policy; explaining to someone why length beats symbols.

Inputs

Field names are the actual form parameters, verified against source.

Field	種類	Required	Notes
pw	text	required	The candidate password.

What you get back

Entropy in bits with crack-time estimates at several attack rates.

活用例

Input

P@ssw0rd123!

Output (abridged)

ENTROPY: 38 bits -- WEAK

  It looks compliant: 12 chars, upper, lower, digit, symbol. It passes
  almost every corporate policy. It is still weak.

  Why: the substitutions are the ones everyone makes. a->@, o->0, plus a
  trailing '123!'. Cracking rule sets apply these transformations to a
  dictionary automatically -- the character-class variety is worth
  almost nothing against a real attack.

CRACK TIME
  Online (100/s, throttled)       ~87 years
  Offline bcrypt (10k/s)          ~10 months
  Offline MD5/GPU (10 billion/s)  ~0.03 seconds

COMPARE: 'correct horse battery staple' = 44 bits, longer to crack, and
easier to remember. Length beats symbol soup -- the point NIST
SP 800-63B has been making since 2017.

How it works

Deterministic entropy calculation. Local — the value is not transmitted or stored.

Limits

Read live from the platform configuration.

Rate limit

30 requests / 60s (platform default)

Limitations — what it does なし do

Entropy assumes an attacker who does not know you. A password derived from your dog's name has high calculated entropy and low real strength. Never enter a password you actively use.

プライバシー

Nothing is stored or logged. Still: do not paste a password you are actively using anywhere.

Standards

NIST SP 800-63B