The entropy of a password (or a passphrase) measures how unpredictable it is or how much solid it is.

Its value is represented in bits of entropy where lower values represent a weak password (or passphrase) and higher values represent a secure one.

  1. “12345678”
  2. “aR6(&CY2Rx*yv#d*”
  3. “Hersir Calkage Insider Sposhy Zebecks”

As you can see, “12345678” is clearly the weakest password and scores just 25 bits of entropy, while a complex password as “aR6(&CY2Rx*yv#d*” scores 105 bits of entropy.


A passphrase like “Hersir Calkage Insider Sposhy Zebecks” scores 211 bits of entropy and it will take several centuries to get cracked.

Please, take into account that this sample passphrase has been calculated with the default settings as used as in the home page of this website: if you want more options, you could reach even higher scores by adding numbers, more words and punctuation in the full featured generator page.

As example, the passphrase “My Dear Son, Richard, Was Born In April 2004” manages to score 290 bits of entropy!