Alternatives to O&O Defrag
A commercial Windows defragmenter that optimizes drives in the background to speed up startup. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
O&O Defrag
A commercial Windows defragmenter that optimizes drives in the background to speed up startup.
Replacements
Listings that take over the same core job as O&O Defrag.
UltraDefrag
A portable disk defragmenter for Windows with file placement, disk health monitoring and cleanup tools.
UltraDefrag is also commercial and Windows only, with a portable edition, per-file defragmentation, disk health monitoring and Windows update cleanup.
Wise Disk Cleaner
A free Windows tool that removes junk files, wipes browser traces and defragments disks.
Wise Disk Cleaner is free Windows software with a built-in defragmenter plus junk and browser trace cleanup, but no automatic background optimization is listed.
Similar software
Related functionality, not a direct replacement.
Microsoft PC Manager
Microsoft's free Windows app for cleaning up storage, managing pop-ups and running quick system checkups.
CrystalDiskInfo
Reads the health data your drives already record and tells you plainly whether one is dying.
TreeSize Free
Shows which folders are eating a Windows drive, ranked largest first, without a scan that takes all afternoon.
