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Password Generator
Strong random passwords, passphrases and custom random strings, made on your device.
Free tools that run in your browser. Nothing you type, open or create is uploaded to NerdBible or anyone else.
Random tokens, keys and codes of any length from any alphabet. Each character is picked with the Web Crypto random number generator and rejection sampling, so every character in the alphabet is exactly equally likely.
Made with your browser's cryptographic random number generator. Nothing is sent or stored. Passphrase words: the EFF short word list (CC BY 3.0).
How to use it
- Pick Password for a random string, Passphrase for a run of words that is easier to type and remember, or Custom for tokens and codes from your own alphabet.
- Set the length or the number of words. 16 characters or 6 words is a good minimum for an important account.
- In Custom, set the length, how many you need (up to 1,000) and the characters to use, and check the bits of randomness shown.
- Press Copy and paste it into the sign-up form or your password manager, or download a list of custom strings as a text file.
Questions
Is this password generator safe to use?
Yes. The password is made in your browser with the Web Crypto random number generator and never leaves your device. The page sends nothing to NerdBible or anyone else.
How long should a password be?
At least 16 random characters for important accounts, or a passphrase of six or more random words. Length matters more than adding symbols.
Password or passphrase?
Both are strong when they are random. A passphrase is easier to type on a phone and to remember; a random password packs more strength into fewer characters.
Is a custom string random enough for API keys and tokens?
Yes. It uses the same cryptographic random generator browsers use for encryption keys, with rejection sampling so no character is more likely than another. For a key, aim for at least 128 bits: 22 letters and digits, or 32 hex characters.
Do I need a different password for every site?
Yes. When one site leaks, attackers try the same email and password everywhere else. A password manager remembers a unique password for each site so you do not have to.
About this tool
About the password generator
A strong password is one nobody could guess, and the surest way to get one is to let a computer pick it at random. This generator offers three styles in tabs.
- Password: a random mix of upper and lower case letters, numbers and symbols, 8 to 64 characters, with an option to avoid look-alike characters such as 0 and O.
- Passphrase: three to ten random words from the EFF short word list, joined by a hyphen, space, dot or underscore. Easier to type on a phone and to remember.
- Custom: random strings in bulk from character sets you choose or your own alphabet, handy for API keys, tokens and test data.
How the randomness works
Every character or word is drawn with your browser's cryptographic random number generator, the same source used for encryption keys. The strength meter shows roughly how many bits of randomness the result holds: around 80 bits or more is very strong.
Practical tips
Use at least 16 characters or six words for accounts that matter, such as email and banking. Never reuse a password across sites: when one site leaks, attackers try the same login everywhere else. A password manager can remember a different one for each account, so the only one you need to know is its master passphrase.
Passwords are generated on your device and are never sent to or stored by NerdBible.
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- Bcrypt Generator & VerifierHash a password with bcrypt or check one against a hash.
- Encrypt & Decrypt Text or FilesLock text or a file with a password using AES encryption, and unlock it again.