Password Generator
This password generator creates cryptographically random passwords of 8–64 characters or multi-word passphrases, and shows an estimated strength in bits of entropy.
About this tool
This password generator creates cryptographically random passwords of 8–64 characters or multi-word passphrases, and shows an estimated strength in bits of entropy.
How to use it
- Choose Random Password or Word Passphrase.
- For a password, set the length and pick uppercase, lowercase, numbers and symbols; for a passphrase, set the number of words, a separator and optional capitalisation or number.
- Check the entropy estimate and click Regenerate until you like the result.
- Click Copy and store it in your password manager.
Good to know
- Randomness comes from the Web Crypto API crypto.getRandomValues, a cryptographically secure generator.
- Entropy is estimated as length × log2(character-set size); with all four character sets a 16-character password is roughly 103 bits.
- The strength label is Weak below 40 bits, Fair below 60, Strong below 80 and Very Strong at 80 bits or more.
- Passphrases are built from random words, optionally with a random 3-digit number appended for extra entropy.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Frequently asked questions
How long should a password be?
For most accounts 16 or more random characters is a strong choice. Longer passwords add much more strength than extra symbol types.
Are passwords generated here stored or sent anywhere?
No. They are generated on your device in the browser and are never transmitted, logged or saved.
Passphrase or random password — which is better?
A random password packs more entropy per character; a passphrase is easier to type and remember. Both are strong if they are long enough and truly random.
What does the entropy number mean?
It estimates how many guesses an attacker would need, in bits: each extra bit doubles the number of possibilities.