With version 2.1 on both iOS and macOS, PSWD – Password Generator can calculate the entropy for a password preset in real time as you configure password options, adding to its continuously expanding set of features.
Password entropy is the measurement for generating less predictable passwords. The higher the entropy, the harder it is to crack the password. Entropy gets higher as you add more characters to the pool that you choose from to create the password, or as you make the password longer. As you configure options, PSWD calculates the entropy, displays it to you and determines the strength of the resulting password according to the following industry-accepted entropy chart:
- Less than 28 bits: Very weak, should only be used on trivial systems
- 28 to 35 bits: Weak, can be used for desktop login passwords
- 36 to 59 bits: Mediocre, can be used as company login passwords as long as necessary precautions are taken, especially for the lower entropy values
- 60 to 127 bits: Strong, can be used as passwords for anything
- 128 bits or above: Very strong, if you use a password manager, use this for a nearly impossible to crack password
The default preset for PSWD creates passwords with 174.4 bits of entropy, which cannot be cracked even in quadrillions of years using a home computer.
For more info on password entropy, and to learn how it is calculated, you can visit this page.