APFS was initially only available on SSDs (which as we’ve already said, shouldn’t be defragged anyway), but it arrived on hard drives and Fusion drives in 2018 with Mojave.

A year later, in 2003, Hot File Adaptive Clustering arrived, which identifies files that are frequently accessed but rarely updated and moves them to a special area of the drive, defragging them during the process.Īpple then introduced APFS (Apple File System) in High Sierra in 2017. Then in Mac OS X 10.2, which arrived in 2002, the system got even cleverer at avoiding fragmentation. HFS+, which was introduced in 1998, could defrag files on the fly thanks to Hot File Clustering. Mac do not need to be defragmented because the file system (initially HFS+ and more recently APFS) prevents fragmentation and automatically defrags files if necessary – if the file has more than eight fragments, or is smaller than 20MB, it will be automatically defragged.

If you are running High Sierra or Mojave, and your file system has been changed to Apple’s newer APFS, you will not be able to use any third party tools to defrag your Mac as there are none that work.

Your Mac operating system does not predate 2002 (if it does can we suggest you update your Mac!).

If any of the following applies to you we would suggest that defraging is not the solution to your problem: As we’ll explain below, you probably don’t need to defrag your Mac.

Disk defrag pro