Suggestions appear as you type. Use the up and down arrows to choose one and Enter to open it.

This page's audience our own tag's counts — open to see them
–Visits
–Page views
–Clicks to vendors
–Time on page
–Reading now
Clicks to vendors, by tool
  • –
Top countries
  • –
Devices
  • –

– · visits, page views and clicks counted by our own tag, which counts more than our checked analytics; every figure rounded down · how we count

Head-to-head · Disk Defragmentation Software

IObit Smart Defrag vs UltimateDefrag 6

  • Updated Oct 2026
  • Both researched from official sources
  • 4 checks side by side
Higher score IObit Smart Defrag #1 in Disk Defragmentation Software 9.4/10 Free plan Free plan✓ 3 of 3 features Visit IObit
UltimateDefrag 6 #6 in Disk Defragmentation Software 8.2/10 Paid ✓ 3 of 3 features Visit UltimateDefrag

IObit Smart Defrag leads on 1 check, UltimateDefrag 6 on 0, and 3 are even. Who comes out ahead on the 4 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreIObit Smart Defrag · 9.4/10
  • Free planonly IObit Smart Defrag

IObit Smart Defrag scores higher on our rubric for disk defragmentation software: 9.4 against 8.2 out of 10; our editors rank them #1 and #6.

IObit Smart Defrag offers free plan; UltimateDefrag 6 doesn't.

IObit Smart Defrag is the better fit for windows users wanting HDD and SSD optimization. UltimateDefrag 6 is the better fit for strategic FAT32 and NTFS optimization.

  • IObit Smart Defrag fits best

    Windows users wanting HDD and SSD optimization

  • UltimateDefrag 6 fits best

    Strategic FAT32 and NTFS optimization

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Side by side

Feature IObit Smart Defrag 9.4/10 Visit ↗ UltimateDefrag 6 8.2/10 Visit ↗
At a glance
Editor score 9.4 8.2
Ranking #1 in Disk Defragmentation Software #6 in Disk Defragmentation Software
Best for Windows users wanting HDD and SSD optimization Strategic FAT32 and NTFS optimization
Pricing model Free plan + paid Paid
Starting price — $29.95 one-time
Free plan ✓ (best) —
Free trial — —
Money-back guarantee 60 days 30 days
Deployment Desktop Desktop
Platforms Windows Windows
Built for Solo, Small business Solo, Small business
Features IObit Smart Defrag 3/3 · UltimateDefrag 6 3/3
Scheduled optimization ✓ ✓
Automatic optimization ✓ ✓
Boot-time optimization ✓ ✓
Specs
Drive types Both Both
Filesystem support Not checked yet Multi-filesystem
Maximum drive count Not checked yet Not checked yet
Our review
Pros
  • Supports HDD defragmentation and SSD trimming
  • Includes scheduling, automation, and boot-time defragmentation
  • Free edition includes game optimization and scheduled defrag
  • Supports FAT32, NTFS, HDD, SSD, external, and RAID configurations
  • Combines scheduling, automation, boot-time placement, and file-level jobs
  • Includes simulation mode, command-line directory defragmentation, and three-PC licensing
Cons
  • Windows-only platform support
  • Advanced optimization features require Pro
  • Pro 1 PC pricing is not shown here
  • Windows-only software with no listed support for other platforms
  • The regular license price is a $29.95 one-time purchase
  • The trial operates only in simulation mode and makes no drive changes
Our verdict

IObit Smart Defrag is Windows desktop software for analyzing and optimizing HDDs and SSDs. It suits Windows users who want one tool for traditional defragmentation, SSD trimming, scheduled maintenance, and drive-focused optimization. Its…

Read the review →

UltimateDefrag 6 is Windows desktop software for defragmenting and optimizing hard drives and SSDs. It is aimed at users who want more control than a basic drive-maintenance utility, particularly when working with FAT32 or NTFS volumes and…

Read the review →
  1. IObit Smart DefragDisk Defragmentation Software 9.4Free plan
  2. UltimateDefrag 6Disk Defragmentation Software 8.2Paid

Strengths and trade-offs

  • IObit Smart Defrag — where it wins

    • Supports HDD defragmentation and SSD trimming
    • Includes scheduling, automation, and boot-time defragmentation
    • Free edition includes game optimization and scheduled defrag

    Where it doesn't

    • Windows-only platform support
    • Advanced optimization features require Pro
    • Pro 1 PC pricing is not shown here

  • UltimateDefrag 6 — where it wins

    • Supports FAT32, NTFS, HDD, SSD, external, and RAID configurations
    • Combines scheduling, automation, boot-time placement, and file-level jobs
    • Includes simulation mode, command-line directory defragmentation, and three-PC licensing

    Where it doesn't

    • Windows-only software with no listed support for other platforms
    • The regular license price is a $29.95 one-time purchase
    • The trial operates only in simulation mode and makes no drive changes

More comparisons

All disk defragmentation software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update