Password Generator

What you can do

• Generate a strong random password with lowercase, uppercase, digits and symbols.
• Set the exact length, from 4 to 128 characters.
• Edit the symbol set, or exclude ambiguous characters like 0, O, 1, l and I.
• Build a memorable diceware-style passphrase from the EFF short wordlist.
• Check the entropy and estimated crack time of your settings.
• Generate up to 100 passwords at once, then copy or download the whole batch.

How to use the Password Generator

1. 1Pick a mode: random characters or a passphrase.
2. 2Tune the settings. Length and character sets in one mode, word count, separator and capitalization in the other.
3. 3Read the strength meter to see the entropy and how long cracking would take.
4. 4Copy a password with the button next to it, or regenerate until you get one you like.
5. 5For a batch, set how many you need and use Copy all or Download.

How the randomness works

Every character and word is drawn from the Web Crypto API's cryptographically secure random number generator, the same source password managers use. Draws go through rejection sampling, so no character is ever slightly favored the way a naive modulo mapping would. Math.random is never involved.

The option to require one character from each enabled set picks those characters first, fills the rest from the full pool, and then shuffles the result with the same secure randomness, so the guaranteed characters end up at unpredictable positions.

What the entropy number means

Entropy measures how many equally likely outputs the current settings can produce. Each extra bit doubles the number of guesses an attacker needs, so a 60-bit password is a billion times harder to crack than a 30-bit one. The meter computes the exact keyspace of your settings, including the small reduction caused by requiring a character from every set.

The crack time assumes an offline attacker testing ten billion guesses per second, which matches a serious GPU rig attacking a fast hash. Sites that store passwords with a slow hash, or that rate-limit login attempts, push the real time far higher. The estimate is the average case, half the keyspace searched.

Random characters or a passphrase

Random character strings pack the most entropy per character, which suits anything a password manager fills in for you. Passphrases trade some length for memorability. The words come from the EFF short wordlist, 1,296 short common words picked to be easy to spell, and each word adds about 10.3 bits. Five words reach roughly 52 bits and six words about 62, a solid choice for a password you actually have to type or remember.