Strong password generator online
Generate strong, random passwords with the length and characters you choose. They are created on your device: never sent and never stored.
Strength with these options: strong (102 bits).
A desktop machine with 16 reels behind a window. Each reel is engraved with 84 characters and shows one. On the right, a button that spins them; in front, a ruler with a cursor marking how many reels are in use; on top, four character-type selectors and a dial whose needle reads the bits of entropy. Enter or Space generates a password; the arrow keys change its length.
How to use it
- Choose the length with the slider.
- Tick the types of characters you want to include.
- Click “Generate password” and copy it into your password manager.
Frequently asked questions
Is it safe to generate passwords on a website?
Here it is: the password is created in your browser with the system’s cryptographic generator and is never sent, logged or stored anywhere.
How long should a strong password be?
At least 12 characters; 16 or more for important accounts. Each extra character multiplies the time it would take to guess it.
What does the strength in bits mean?
It is the entropy: how many possible combinations there are. From 80 bits up, a random password is considered strong against brute-force attacks.
How do I remember such a long password?
You do not have to: store it in a password manager and use a different one for every account.
What makes a password strong
Two things: being random and being long. A password made up by a person follows predictable patterns (a word, a year, a symbol at the end) that attack tools try before anything else. A randomly generated one has no pattern: the only way to guess it is to try every combination.
How many combinations there are is measured in bits of entropy: the length multiplied by the base-2 logarithm of the number of different characters to choose from. Each bit doubles the attacker’s work, which is why adding length is far more effective than adding a symbol.
| Length | Entropy | Rating |
|---|---|---|
| 8 characters | 51 bits | fair |
| 12 characters | 77 bits | fair |
| 16 characters | 102 bits | strong |
| 20 characters | 128 bits | strong |
| 24 characters | 153 bits | strong |
How to use the passwords you generate
Use a different one for each account. Data breaches are common, and the first thing someone who gets hold of a password does is try it on the same person’s email, bank and social media. If every account has its own, a breach affects only one.
There is no need to memorise them: keep them in a password manager and remember only the master password. On important accounts, also turn on two-step verification, which protects you even if the password ends up in the wrong hands. If a site does not accept symbols, untick that box and make up for it with a few more characters of length.
