A card, USB stick or external drive you sell or give away can still hold files you deleted from it. Deleting only marks the space as free. Reco’s Before You Pass It On shows you what a stranger with a recovery app could get back, writes over the empty space where those files were, and then looks again, so you see the difference rather than take Reco’s word for it.
The files you can still see on the drive aren’t touched. It’s free.
This or Forget for Good?
- Keeping the files on the drive, and just clearing what was deleted: use Before You Pass It On.
- Emptying the drive completely: drop the whole drive on Forget for Good, which writes over every byte and formats it again. Or erase it in Disk Utility with Security Options, where Apple offers them.
How it works
- Open Before You Pass It On from More ways Reco can help or the Tools menu, and choose the drive.
- Click See what’s recoverable. Reco looks at the drive the way a stranger would at first glance, and tells you how many deleted files it can still see.
- Type the drive’s name to confirm. This is the step that can’t be undone: what was deleted from the drive can’t be recovered afterwards, by Reco or anything else.
- Click Clear the empty space. Reco fills the empty space with zeros, then removes the fill. If the drive has several volumes, the empty space of each one that’s open in Finder is cleared. You can pause, resume or stop; stopping is safe, and your files stay as they are.
- Read the before and after. Reco looks again and shows both counts and how much empty space was written over.
Honest limits
- The count comes from a quick look. It sees files deleted the ordinary way. A deep scan usually finds more, so even a count of zero is worth clearing. Afterwards, Reco suggests a deep scan from the main screen if you want to be thorough.
- Names can survive. Some entries stay in the drive’s own list of files, which clearing empty space doesn’t rewrite. Their contents are gone, but names may still show. Erasing the whole drive removes those too, and Reco says so when it happens.
- SSDs: writing over free space can’t reach every old copy on an SSD. Reco warns you; erase the whole drive in Disk Utility instead.
- Not your Mac’s startup disk. Its SSD already clears deleted data on its own (TRIM), and filling it up would make macOS unstable. To pass on a whole Mac, use System Settings ▸ General ▸ Transfer or Reset ▸ Erase All Content and Settings.
- Not a drive you’re recovering from. Clearing it would destroy exactly what’s being recovered, so Reco refuses until you’ve finished.
Questions
Can someone recover my files from a USB stick or SD card I give away?
Often, yes. Deleting files or a quick format leaves their data in place until it’s overwritten, and free recovery apps can find it. Clearing the empty space, or erasing the drive with an overwrite, stops that.
Will clearing the empty space delete the files I can see?
No. Before You Pass It On only writes over the empty space, where deleted files were. The files you can see on the drive stay as they are.
Does this work on SSDs?
Not fully. SSDs move data around inside, so writing over free space can’t reach every old copy, and Reco says so. To pass an SSD on, erase the whole drive in Disk Utility instead.
How long does clearing take?
About as long as filling the drive: minutes for a small card, hours for a big disk.