Microsoft Defender vs Avast
Microsoft Defender leads Avast by 0.1 points overall (8.1 vs 8.0).
8.1/10, Very good
8.0/10, Very good
Criterion by criterion
Where each one wins
Microsoft Defender8.5
Tested in AV-TEST and AV-Comparatives series with generally good results.
Protection record
35% weight
Avast8.5
Regularly participates in AV-TEST and AV-Comparatives with solid results.
Microsoft Defender7.0
Lab reports have shown more slowdown in some tasks than the lightest rivals.
System impact
15% weight
Avast7.5
Moderate system impact in lab reports.
Microsoft Defender10.0
No extra cost on Windows.
Value for money
20% weight
Avast8.5
Capable free tier; paid upgrades are reasonably priced.
Microsoft Defender5.5
Core protection and firewall; few consumer extras.
Extra features
15% weight
Avast7.5
Free tier includes web protection; VPN and extras need upgrades.
Microsoft Defender8.0
On by default with nothing to install, but Windows only.
Ease of use & platforms
15% weight
Avast7.0
Apps on all major platforms, with frequent upgrade prompts.
Published facts
Side by side
| Fact | Microsoft Defender | Avast |
|---|---|---|
| Free version | Yes | Yes |
| Money-back window | Not published | Not published |
| Free trial | Not published | Not published |
| In AV-TEST or AV-Comparatives tests | Yes | Yes |
| Main platforms | Windows (built in) | Windows, macOS, Android, iOS |
| Company base | United States | Czech Republic |
Verdict
Which should you pick?
Choose Microsoft Defender if…
You want something best for windows users who want solid no-cost protection.
- + No extra cost
- + Enabled by default
- + Tested by major independent labs
Choose Avast if…
You want something best for users wanting a full-featured free antivirus.
- + Full-featured free tier
- + Covers all major platforms
- + Regular lab participation
Checked 1 Nov 2026.
Questions
Microsoft Defender vs Avast: quick answers
Is Microsoft Defender better than Avast?
Microsoft Defender leads Avast by 0.1 points overall (8.1 vs 8.0). Microsoft Defender scores higher on value for money, ease of use & platforms. Avast scores higher on system impact, extra features.
Who should choose Avast over Microsoft Defender?
Avast is best for users wanting a full-featured free antivirus. Microsoft Defender is best for windows users who want solid no-cost protection.
How were Microsoft Defender and Avast scored?
Both were scored on the same 5 weighted criteria for antivirus software, using public information such as published plans and terms. We do not lab-test products.