How secure is my email password?? How quickly can my app account be hacked?? And how long does it take a hacker to crack my iCloud password?? Some tools on the Internet aim to provide answers to these questions. However, one may wonder how useful it is to enter one’s (actually secret) passwords into a web tool. That’s why in this guide you’ll get links to a few of the password checkers as well as one or two tips on how to use them. So your passwords stay secret, and you still know how secure they are 
How long does it take a hacker to crack my password?? How quickly the password can be cracked by a brute force attack? Find out here.
How secure is my password?
How secure is the password for the e-mail account, for an app or for the iCloud, you can theoretically determine with an infographic. These are available from Hive Systems, among others, or as an image below. From this you can see that the most secure passwords are long, contain upper and lower case letters, have numbers and also contain special characters (&, %, $, #, + or the like) have. A password is really secure if it is highlighted in green in the infographic, i.e. if it has more than 13 characters. Purple and red cells in the table mean that the password can be cracked very quickly.
Source: hivesystems.io/blog/are-your-passwords-in-the-green
How quickly can a hacker crack my password?
In addition to the chart that tells you how many letters, numbers and special characters you should use, there are also web tools with text boxes where you can enter your passwords. They will then be checked in real time, showing you directly how quickly a hacker can crack the password – not by mere trial and error, but with a brute force attack (s. u.). Here’s a tip: If the original password STEVE&apple941 is, enter something like HELGA§846micro instead. So you use the same length and number of upper case letters, lower case letters, special characters and numbers, but you change the order and the characters themselves.
- How Secure Is My Password (with advertising): Click here
- How Secure Is My Password (successor of the above page): Click here
- Password Checker (Also checks if the password has been leaked somewhere): Click here
What is a brute force attack?
"Brute force" means something like "brute force.". The hacking method, so named, relies on trying as many password possibilities in as little time as possible. Of course, single letters, letter-number combinations and frequently used words come into play first. So a long password consisting of only one word and a string of numbers (for example "password12345") is not as secure as an equally long string of characters that is more complex and randomized (for example "1PW2#+34apple"). You can find an insight about the connection between brute force attacks and password lengths with this link.