Compare software

O&O Defrag vs Auslogics Disk Defrag: catalog facts
O&O Defrag	Auslogics Disk Defrag
Paid Commercial software sold by O&O Software.	Free Disk Defrag is free; the separate Disk Defrag Ultimate edition is paid.
Windows	Windows
Optimizes drives automatically in the background Maintained by an established Windows software vendor	Free alternative to the built-in Windows defragmenter From a long-running Windows utilities developer
Windows only Paid software	Windows only Defragmenting brings little benefit on SSDs
Downloadable app	Downloadable app
Closed source	Closed source
License not stated	License not stated
Not stated if an account is needed	No account needed
Works offline	Works offline
Official website Full listing and sources Checked September 24, 2026	Official website Full listing and sources Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.