Password Generator
Create a cryptographically random password from the character sets you choose, with length up to 128, an option to skip look-alike characters like i, l, 1, O and 0, and a passphrase mode built from a 1,000-word English list. Each result shows its entropy in bits, calculated from the length and the character pool. Generation uses your browser's crypto API; nothing leaves this page.
About this tool
Generates passwords and passphrases with your browser's crypto API and reports the entropy each result carries. Password mode builds from the character sets you pick, up to 128 characters, with options to exclude look-alikes (i, I, l, 1, O, 0) or force a letter first. Passphrase mode picks words from a 1,000-word English list — easier to type and remember, with an optional capitalized form and a two-digit suffix. The entropy figure is calculated from the pool size and length; no crack-time guess is shown, because real crack time depends on the attacker, not the math.
When to use it
Questions
What does the entropy number mean?
It is log2 of the character-pool size, multiplied by the length — the information content a brute-force attacker would have to search. A 20-character password from all four sets carries about 129 bits; a 4-word passphrase from this list carries about 43 bits plus any suffix. Longer or bigger pools mean more bits; there is no other trick.
Why choose a passphrase instead of a password?
Entropy comes from random selection, not from symbol soup. Four random words are far easier to memorize and type than twenty random symbols, and can carry plenty of entropy — add more words rather than mangling them with substitutions.
Is excluding look-alike characters less secure?
Slightly — a smaller pool means fewer bits per character — and the entropy readout drops accordingly. It is a trade-off for passwords you will read aloud or transcribe from paper. For copy-pasted secrets, leave it off.