What is a strong password generator?
A password generator creates, in a fraction of a second, a random password that is extremely hard to guess or crack — instead of relying on weak choices like birthdays, pet names or “123456”. This tool gives you full control over the length and the character types, and shows the strength level, entropy in bits and an estimated time to crack.
How to use the tool
- A new 16-character password appears automatically when the page loads.
- Move the Length slider or type a number from 4 to 128. We recommend at least 16 characters for important accounts.
- Pick the character types: uppercase, lowercase, numbers and symbols. More variety means more strength.
- Enable Exclude look-alike characters if you will ever type the password by hand, to avoid confusing I with 1 or O with 0.
- If a website rejects certain symbols, type them in Exclude specific characters.
- Need several passwords? Set How many passwords up to 20.
- Click Copy, paste it where needed and save it in a trusted password manager.
What makes a password strong?
Password strength depends on two factors: length and character variety. We measure it with “entropy”, calculated as the length multiplied by the base-2 logarithm of the number of possible characters. An 8-character lowercase password has about 38 bits and can be cracked in minutes on modern hardware, while a 16-character password using all four types exceeds 100 bits and would take millions of years to brute-force. Notice that adding length increases strength faster than adding a new character type.
Is the generation really secure?
Yes. The tool uses the browser’s built-in Web Crypto API (crypto.getRandomValues), a cryptographically secure random number generator — not the predictable Math.random function. We also use rejection sampling to avoid bias toward particular characters, guarantee at least one character from each selected type, and then shuffle the result. Most importantly, everything happens on your device: passwords are never sent to our servers or stored anywhere.
Golden rules to protect your accounts
- Use a unique password for every account, so one breach cannot unlock the others.
- Store passwords in a password manager rather than on paper or in phone notes.
- Turn on two-factor authentication (2FA) for email, banking and your online store.
- Change a password immediately after a breach alert or suspicious activity.
- Never share passwords over chat or email.
Who is it for?
It is useful for every internet user, and especially for online store owners, site administrators and developers who need strong credentials for dashboards, databases, hosting accounts and payment gateways — where a single compromise can be very costly.