Generate strong passwords you can trust
Weak and reused passwords are the most common way accounts are taken over. This password generator creates long, random passwords that are practically impossible to guess or brute-force. It uses your browser's cryptographically secure random number generator, and the passwords exist only on your screen — they are never sent over the network or saved anywhere.
Features
- Length from 4 to 128 characters, adjustable with a slider.
- Character sets: uppercase, lowercase, numbers and symbols, each guaranteed to appear at least once.
- Avoid ambiguous characters to prevent confusing
0/Oor1/l/I. - Strength meter with entropy so you can see how strong a configuration really is.
- Bulk generation of up to 50 passwords, handy when setting up several accounts or test users.
- Unbiased randomness: values are drawn with rejection sampling, so every character is equally likely.
What makes a password strong
A password's strength depends on how many possibilities an attacker must try. That number is the size of the character pool raised to the power of the length. With all four character types enabled this tool draws from 88 characters, so each one adds about 6.5 bits of entropy:
| Length | Lowercase only (26) | All four types (88) |
|---|---|---|
| 8 | 38 bits | 52 bits |
| 12 | 56 bits | 78 bits |
| 16 | 75 bits | 103 bits |
| 20 | 94 bits | 129 bits |
Modern attackers can test billions of guesses per second against stolen password hashes, so aim for at least 80 bits for important accounts. As the table shows, adding length is the most effective way to get there.
Good password habits
- Use a password manager to store a unique, generated password for every site. You then only need to remember one strong master password.
- Turn on two-factor authentication wherever possible; it protects you even if a password leaks.
- Don't modify old passwords by adding a number at the end — attackers' tools try those variations first.
- Generate, don't invent. People are poor at randomness; names, dates and keyboard patterns are among the first things cracking tools test.
Need random numbers or IDs instead? Try the Random Number Generator or the UUID Generator.