These two tools overlap less than people assume. Used together they cover almost everything; used alone, each leaves an obvious gap.
Scope
Disk Cleanup is built around Windows itself: update leftovers, delivery optimization files, previous installations, the Recycle Bin, system error dumps. BleachBit starts where that ends — browser profiles, application caches, chat clients, media players, office suites, development tools.
Control
Disk Cleanup shows categories and estimated sizes. BleachBit shows the individual files it intends to remove, before removing them. If you want to know exactly what is going, only one of these tools tells you.
Safety
Disk Cleanup is the more conservative option and hard to misuse. BleachBit gives you enough rope to clear your saved passwords if you check the box that says so. The preview step is the safeguard, and it works — provided you use it.
Results on a typical PC
On a Windows 11 machine a year after a feature update, Disk Cleanup with system files enabled often recovers far more in one pass, thanks to the previous installation folder. On a machine that upgrades regularly and browses heavily, BleachBit finds more in the day-to-day layers. Neither number is universal, which is the honest answer.
Which should you run?
- Disk Cleanup as administrator, first, for the big one-time system items,
- BleachBit second, for application-level leftovers,
- Storage Sense left enabled so temporary files do not accumulate again.
What neither one does
Neither tool removes large personal files, unused games, or duplicate downloads — the categories that most often fill a modern drive. For those, see how to free up disk space on Windows 11.