How this tool works
The selected character set limits which symbols may appear. Each position is independently sampled using the browser’s cryptographic random API. The search-space metric is length times log base two of the alphabet size.
For each character, draw one uniform index from the allowed character set using the browser crypto API.A worked example
Selecting length 20 returns a 20-character password. Generate again to draw a fresh value from the same character pool.
Good to know
Allowed character pools do not enforce at least one character from each class. The page depends on browser cryptographic randomness.
Reference: Web Cryptography random-values API (opens in a new tab) ↗
How the inputs affect the result
Use a password manager to store generated passwords and give each account a separate value. If a site rejects a symbol, adjust the alphabet and draw a new password.
Use a longer value when a site restricts symbols.
Where the calculation applies
Allowed character pools do not enforce at least one character from each class. The page depends on browser cryptographic randomness.
For a related calculation, see the Random integer and decimal generator.
Read more: Web Cryptography random-values API (opens in a new tab) ↗
A few questions, answered
Why omit look-alike characters?
If a password must be typed manually, removing similar-looking characters can reduce transcription mistakes. A longer password can compensate for the smaller alphabet.
What does the “Long letters-and-digits password” setting illustrate?
Use a longer value when a site restricts symbols.