Ccleaner Free __top__: Space Wipe

You’ve seen it in CCleaner: under Tools > Drive Wiper , the option to wipe “Free Space Only.” It sounds harmless. Even responsible. But beneath that simple checkbox lies a complex, often dangerous interaction with how modern storage works.

On an HDD: Performance returns to normal. On an SSD: The drive now thinks all free space is actually used (because you wrote to every logical block). The controller doesn’t know it’s garbage. Next time you write real files, the drive may need to garbage-collect first, causing temporary slowdowns. ccleaner free space wipe

Let’s cut through the marketing and look at what this feature actually does—and what it doesn’t. When you delete a file normally, Windows just marks that space as available . The data remains until overwritten. A free space wipe overwrites every sector marked as “free” with garbage data (usually zeros, random bytes, or multiple passes). You’ve seen it in CCleaner: under Tools >