Erase Free Space Mac

Choose apple menu about this mac then click storage.
Erase free space mac. Each segment of the bar is an estimate of the storage space used by a category of files. Move your pointer over each segment for more detail. Many mac users running a modern version of os x el capitan have noticed the secure erase free space feature has gone missing from disk utility. What the erase free space feature did and still does in prior versions of mac os x was overwrite the free space on a drive to prevent file recovery adding a layer of security and privacy to file removal much in the way that secure empty trash performed a similar function of overwriting data after removal.
Just install super eraser for mac on your mac and launch it. Select a volume you want to erase the free space on. With the help of super eraser for mac you can easily erase free disk space of mac hard drive or storage media device. Easily erase free disk space on mac.
It will show you three data erasure modes just select wipe free space and select the hard drive you want to erase.