That's why you may need a Mac cleaner software which can help you free up a decent amount of disk space in just a few minutes. Unfortunately, cleaning a Mac isn't easy as it sounds. It is important to keep your Mac hard drive clean (not the outside, but inside) to make the most of every gigabyte. A modern MacBook might have a solid-state drive with just 128 GB or 256 GB of storage, which means you'll see that 'Your disk is almost full' error sooner rather than later.