How to Defrag a Mac to Make It Run Faster

By Nicholas Johnson

As computer files are accessed, saved and overwritten, their pieces become scattered around the hard drive. This holds true for both Macs and PCs. The Mac OS contains built-in defragmentation processes, which means most Mac users don't need to worry about defragging their machine. However, it can be helpful to run an application such as iDefrag to rearrange file pieces into a more organized format. Defragmentation can speed up the performance of your computer, saving you valuable time.

Step 1

Open your web browser and go to the iDefrag website. Download the demo version or purchase the full version. The demo allows basic defragmentation, while the full version includes additional options for more in-depth defragmentation sessions.

Step 2

Open iDefrag. Enter your password and select the volume that you wish to defrag from the left panel.

Step 3

Click "Go" and wait for the defragmentation to finish. Do not open any other applications, as doing so restarts the defragmentation process. The process can take several hours, depending on the size of your hard drive and the amount of fragmentation.

Step 4

Click "Restart" if you are prompted to restart your computer. This happens when the program defragments startup drives.

Tips & Warnings

  • Mac OS X automatically defragments files under 20 MB in size, which accounts for the large majority of most users' files. Defragmentation is only necessary for users such as video or audio editors who have a lot of large files.
  • Do not worry if iDefrag warns you that your device is overheating. iDefrag contains security protocols to allow the system to cool down before resuming defragmentation.