How to create strong passwords (and remember them)
What makes a password strong, how long it should be and how to manage passwords without reusing them.
Secure password generator
Strong random passwords generated on your device.
Runs in your browser
Your password
What it does: Secure password generator
This generator creates random passwords from 8 to 128 characters using crypto.getRandomValues, your browser's cryptographic randomness source. Every character type you select appears at least once.
The password never leaves your device: it is not sent to any server, not stored and not included in analytics.
How to use it
- Choose the length with the slider (16 characters is a good starting point).
- Tick the character types the service where you'll use it accepts.
- If you'll type it by hand, exclude look-alike characters.
- Copy the password and save it in your password manager.
Examples
Email account
20 characters with all four types exceed 120 bits of entropy: practically impossible to guess.
Wi-Fi password you'll read out
16 characters with only lowercase and numbers, excluding look-alikes: easier to type on a TV or games console.
Limits, formulas and assumptions
- Entropy = length × log₂(number of possible characters). Above 80 bits is considered very strong.
- Randomness uses rejection sampling so every character has exactly the same probability.
- Some services reject certain symbols; if sign-up fails, turn symbols off and increase the length.
Frequently asked questions
Is it safe to generate passwords on a website?
Here it is, because everything happens in your browser with the standard crypto API and nothing is transmitted. You can check by going offline: it keeps working.
How long should it be?
At least 12 characters for regular accounts and 16 or more for email, banking and your password manager.
How do I remember such long passwords?
You don't need to: use a password manager and memorise only the master password.
Related guides
Related tools
Random number generatorRandom numbers within a range, with or without repeats. Username generatorOriginal username ideas for social networks and games. Base64 encoder and decoderConvert UTF-8 text and files to and from Base64. QR code generatorCreate and download QR codes as PNG or SVG. Lorem ipsum generatorPlaceholder text by paragraphs, sentences or words. URL slug generatorTurn titles into clean URLs without accents or symbols.