Password Generator
Free to use. Runs in your browser: your files and text are not uploaded.
Create a random password that is hard to guess. Choose the length and which kinds of characters to include.
How to use it
- Set the length. The default is 16 characters.
- Tick the kinds of characters to use: capitals, small letters, numbers and symbols.
- Press Generate, then Copy. Press Generate again for another.
Every password contains at least one character of each kind you ticked.
What “bits of entropy” means
Entropy measures how many guesses an attacker would need. Each bit doubles the number of possibilities. It is worked out as:
length × log₂(number of possible characters)
With all four boxes ticked there are 85 possible characters, and log₂(85) is about 6.4. So a 16-character password has 16 × 6.4 ≈ 103 bits, which means about 2¹⁰³ possible passwords.
| Length | Characters used | Entropy |
|---|---|---|
| 8 | Small letters only (26) | 38 bits |
| 12 | Letters and numbers (62) | 71 bits |
| 16 | All four kinds (85) | 103 bits |
| 20 | All four kinds (85) | 128 bits |
Length adds more strength than variety: each extra character multiplies the possibilities by 85.
Using passwords safely
- Use a different password for every account, so one leak does not open the others.
- Store them in a password manager. Nobody can remember dozens of random passwords.
- Turn on two-step verification where it is offered.
Limits
- Some sites reject certain symbols. If a password is refused, untick Symbols and generate again.
- Clipboard contents can be read by other apps on your device. Paste the password where it is needed soon after copying.
Frequently asked questions
Are the passwords really random?
Yes. They use your browser's cryptographic random number generator, the same source used for encryption keys. They do not use the ordinary random function, which is predictable.
Can this site see my password?
No. The password is created by your browser on your device. It is not sent, logged or stored by us.
How long should a password be?
The US standards body NIST advises at least 15 characters for a password used on its own. A 16-character password using all four character types has about 103 bits of entropy.