OmniDiskSweeper, by The Omni Group, is a great Mac utility for discovering what files are taking up your hard drive space. The software costs $15 and serves one simple, but very helpful, function.
Choose a Drive
To “sweep” a hard drive using OmniDiskSweeper, you simply choose if from the start-up screen. The drives on the computer are listed, along with the total storage, free space and used space for each.
Let OmniDiskSweeper Do the Work
It is often difficult to locate large files on a hard drive, and to determine what folders are taking up the most space. It is often the case that large files can be deleted or archived, but they must be located first. Once you choose a drive, OmniDiskSweeper presents a column list of all the directories (folders) on that drive, with their size listed next to them. The folders are listed in size order, automatically showing you where to dig deeper. Click on a large directory, and see what is taking up space inside that directory, and so on.
Once you have located large files, you can delete them directly within the software, if you don’t need them, of course. You can also drag files into other applications to determine whether or not to delete them. As you delete files, the software automatically recalculates the file sizes of folders. The list of packages a file belongs to are also listed, helping to avoid deletion of files that are essential to the operation of the computer.