Activation Key. A software activation key is a string of letters and/or numbers used to register or activate a software application. You may receive an activation key when you purchase a commercial software program.

The purpose of an activation key is to prevent software piracy by ensuring only users who have purchased a program can use it. Some software programs will not function without a valid activation key, while other programs will run in “trial mode” or with restricted functionality. Registering or activating the software with the activation key removes these limitations.

There is no standard activation key format, but most include

both letters and numbers. They often contain groups of characters separated by dashes for readability. Most license keys contain at least 10 characters, and some may have over 30. Below is an example of a typical activation key:


Developers can implement software activation keys in several different ways. The most basic method is to simply check a key against a database or list of keys. If a user enters an activation key that matches one in the list, the software is successfully activated. A more advanced method is to generate activation keys dynamically based on a user’s registration information (such as an email address). An algorithm in the program can then check the key to see if it corresponds with the email address used to register the software program. Modern software programs often use online activation.