How strong is strong enough?
Strength is measured in bits: every extra bit doubles the number of guesses needed. Around 80 bits is out of reach for any attacker today. A 16-character password using letters, digits and symbols already gets there; 20 characters gives you a comfortable margin.
Length matters more than odd characters. If a site won’t accept symbols, make the password a few characters longer instead.
Made in your browser
The password is made on your own device with crypto.getRandomValues, the same source of randomness your browser uses for encryption. It is never sent to temp.cool or anyone else, and it is gone when you close the page.
Need to give it to someone?
Don’t paste it into email or chat, where it stays for years. Press “Send it safely” and the password goes into a temp.cool link that self-destructs after it is read.