There are various types of unnecessary data that can be cleaned to gain more disk space – such as different caches, log files and cookies – but Redditors don't really like Mac cleaning apps. Additionally some users may want to clean their Mac to solve any performance problems, which they might want to do because they have become accustomed to cleaning their Windows systems. One of the most common reasons for this is the desire to regain disk space when your system gives you a “Startup disk almost full” warning message. How to clean a Mac is one of the most often asked questions by users, and there are several reasons for that. Clean 500MB of Junk for Free Does Reddit Even Like Mac Cleaning Apps?