The OmniDiskSweeper app from the Omni Group identifies the files and folders that are using more than their fair share of space on your Mac's drive.

OmniDiskSweeper
I found out about this little gem from Mike, one of our readers, who was trying to free up some space on his drives. Mike first tried the Mac's built-in ability to display storage utilization by file type.
As Mike pointed out, while this feature shows basic space utilization, it doesn't provide details. After doing some research to find an app that would identify which files and folders are the space hogs, Mike told me about OmniDiskSweeper, which not only reveals the culprits, but also provides the option to delete the buggers. Mike says that while OmniDiskSweeper isn't fancy, it gave him all the information he needs to trim his bulging hard drives.
OmniDiskSweeper sounded like a good candidate for a Tom's Mac Software Pick, so I downloaded the app and quickly determined that I have way too many music and photo files taking up space in my home folder. This is a handy and useful app for tracking drive space utilization, so this week, I give you Mike's Mac Software Pick.
OmniDiskSweeper is free.
See other software choices from Tom's Mac Software Picks.
