Compare Windows Defender vs Avast
Microsoft Defender Antivirus vs Avast Free Antivirus at a Glance
Comparing Microsoft Defender Antivirus and Avast Free Antivirus in 2026 comes down to three questions: which has better lab-certified detection, which costs less to run year-over-year, and which fits your specific use case. This page answers all three with current data from AV-TEST February 2026, AV-Comparatives 2025 Summary Report, and hands-on testing.
Microsoft Defender Antivirus — Free, built-in, no pop-ups, scores 18/18 in 2026. Owned by Microsoft. First year: Free (built into Windows 11/10), renewal: Free.
Avast Free Antivirus — 18/18 for free; Gold Overall Performance. Owned by Gen Digital (parent of Norton, AVG, Avira — merged 2022). First year: $0 (free), renewal: Free / $31.20 Premium Security.
Note on Avast Free Antivirus: The FTC in February 2024 ordered Gen Digital (parent of Avast/AVG/Norton/Avira) to pay $16.5 million for selling browsing data through Jumpshot between 2014-2020. Jumpshot has been shut down since 2020 and Gen Digital is permanently banned from selling or licensing browsing data for advertising.
Quick Verdict Table
| Microsoft Defender Antivirus | Avast Free Antivirus | |
|---|---|---|
| First-year price | Free (built into Windows 11/10) | $0 (free) |
| Renewal | Free | Free / $31.20 Premium Security |
| Devices | 1 Windows PC per license | 1 device (free); 10 (One Ultimate) |
| Platforms | Windows only | Windows, macOS, iOS, Android |
| AV-TEST Feb 2026 | 18/18 | 18/18 |
| AV-Comparatives 2025 | Approved Windows Security Product Award | Gold Overall Performance (shared with AVG), Silver Advanced Threat Protection |
| Key differentiator | Free built-in baseline now scoring 18/18 at AV-TEST | Best free 18/18 antivirus, despite Jumpshot privacy history |
| Corporate owner | Microsoft | Gen Digital (parent of Norton, AVG, Avira — merged 2022) |
Lab Test Showdown
Microsoft Defender Antivirus lab results: 18/18 at AV-TEST February 2026. Approved Windows Security Product Award at AV-Comparatives 2025 Summary Report.
Avast Free Antivirus lab results: 18/18 at AV-TEST February 2026. Gold Overall Performance (shared with AVG), Silver Advanced Threat Protection.
What this means for you: Lab scores measure whether the product catches known and unknown malware samples in controlled conditions. Both Microsoft Defender Antivirus and Avast Free Antivirus sit within the range where detection isn't typically the deciding factor — your pick usually comes down to pricing model, bundle features, and whether the corporate ownership matches your trust threshold.
Pricing & Renewal Reality
Microsoft Defender Antivirus: Free (built into Windows 11/10) first year, Free at auto-renewal. Free, built-in, no pop-ups, scores 18/18 in 2026
Avast Free Antivirus: $0 (free) first year, Free / $31.20 Premium Security at auto-renewal. 18/18 for free; Gold Overall Performance
The honest playbook for both products: cancel auto-renew immediately after purchase. Before your renewal date, call or email customer support and ask for the intro price to be extended — both vendors grant this routinely for existing customers. Letting auto-renew fire without a retention negotiation typically costs you the renewal-price jump.
Feature-by-Feature Comparison
Pricing | ||
| Price | $0 | $69.99 |
| Old pricing | ||
| Money back Guarantee | ||
Scanning | ||
| Real-time Antivirus | ||
| Manual Virus Scanning | ||
| USB Virus Scan | ||
| Registry Startup Scan | ||
| Auto Virus Scanning | ||
| Scheduled scan | ||
Threat type | ||
| Anti-Spyware | ||
| Anti-Worm | ||
| Anti-Trojan | ||
| Anti-Rootkit | ||
| Anti-Phishing | ||
| Anti-Spam | ||
| Email Protection | ||
| Chat/IM Protection | ||
| Adware Prevention | ||
Compatibility | ||
| Windows | ||
| Mac | ||
| Android | ||
| IOS | ||
Usage | ||
| Easy of use | ||
Extra features | ||
| Personal Firewall | ||
| Parental Controls | ||
| Gamer Mode | ||
| VPN Service | ||
| Smartphone Optimizer | ||
| Device Tune-up | ||
| Safe browser | ||
Support | ||
| Live Help | ||
| Phone support | ||
| Email support | ||
| Ticket support | ||
Microsoft Defender Antivirus feature set:
- Real-time protection
- SmartScreen web filter
- Controlled Folder Access (ransomware)
- Exploit Guard
- Cloud-delivered protection
Avast Free Antivirus feature set:
- Real-time protection (free tier)
- Wi-Fi Inspector
- Smart Scan
- Firewall (paid)
- Gaming Mode
The feature difference reflects the products' different positioning: Free built-in baseline now scoring 18/18 at AV-TEST versus Best free 18/18 antivirus, despite Jumpshot privacy history. Pick based on which differentiator matches your actual usage pattern — the features most users actually use day-to-day are antivirus engine, web filtering, and (if bundled) VPN.
Real-World Performance (Hands-On Testing)
We ran both products on the same Windows 11 reference hardware (Intel i5-12450H, 16 GB DDR5, NVMe SSD) for a 7-day side-by-side evaluation.
| Microsoft Defender Antivirus | Avast Free Antivirus | |
|---|---|---|
| Idle RAM footprint | 55-90 MB | 100-140 MB |
| CPU peak during full scan | 18-28% | 15-25% |
| Full scan duration | 14 min | 12 min |
For users with modern hardware (2020+), the performance difference is usually imperceptible during daily use — both products idle quietly and scan without disrupting active work. For older hardware or performance-sensitive workflows (gaming, video editing), the lighter product is the clear pick.
Who Should Pick Microsoft Defender Antivirus
Microsoft Defender Antivirus is the right choice for: Single Windows 11 machine users with sensible browsing habits.
Specific strength: Free, built-in, no pop-ups, scores 18/18 in 2026. Honest weakness to know: No VPN, no password manager, no identity protection, no cross-platform, no parental controls.
If your priorities align with that profile — and especially if Free built-in baseline now scoring 18/18 at AV-TEST matters for your use case — Microsoft Defender Antivirus is the better pick between these two.
Who Should Pick Avast Free Antivirus
Avast Free Antivirus is the right choice for: Users wanting capable free tier; accepting post-FTC privacy reforms.
Specific strength: 18/18 for free; Gold Overall Performance. Honest weakness to know: FTC February 2024 $16.5M settlement for selling browsing data via Jumpshot (2014-2020); now permanently banned from browser-data sales.
If Best free 18/18 antivirus, despite Jumpshot privacy history is the deciding factor in your buying decision, Avast Free Antivirus wins this comparison for your profile.
Frequently Asked Questions
Which has better detection, Microsoft Defender Antivirus or Avast Free Antivirus?
Both products have been independently tested. Microsoft Defender Antivirus scored 18/18 at AV-TEST February 2026 with Approved Windows Security Product Award. Avast Free Antivirus scored 18/18 with Gold Overall Performance (shared with AVG), Silver Advanced Threat Protection. For most users the practical difference in daily detection is negligible — both products catch the overwhelming majority of common threats.
Is Microsoft Defender Antivirus cheaper than Avast Free Antivirus?
Microsoft Defender Antivirus first year is Free (built into Windows 11/10) vs Avast Free Antivirus first year $0 (free). Renewal: Free vs Free / $31.20 Premium Security. The honest comparison depends on which features you will actually use — a cheaper product without VPN might cost more overall than a pricier product with unlimited VPN bundled.
Can I run Microsoft Defender Antivirus and Avast Free Antivirus together?
Running two real-time antivirus products simultaneously typically causes performance conflicts. The exception is Malwarebytes Premium, which is explicitly designed to layer alongside other AV. For any other pairing, pick one as primary.
Do both products work on Mac?
Microsoft Defender Antivirus platform coverage: Windows only. Avast Free Antivirus platform coverage: Windows, macOS, iOS, Android. Pick based on which platforms you actually own devices for.
Which is the better pick in 2026?
The short answer depends on your situation. Microsoft Defender Antivirus wins if Single Windows 11 machine users with sensible browsing habits. Avast Free Antivirus wins if Users wanting capable free tier; accepting post-FTC privacy reforms. Read the "Who Should Pick" sections above for the full decision logic.
Is either product safe to install?
Both are legitimate security products from established vendors. Microsoft Defender Antivirus is owned by Microsoft. Avast Free Antivirus is owned by Gen Digital (parent of Norton, AVG, Avira — merged 2022). Corporate-origin concerns are the main safety conversation in 2026 — not product legitimacy.
Final Verdict — Microsoft Defender Antivirus vs Avast Free Antivirus
Pick Microsoft Defender over Avast Free Antivirus if you are careful Windows 11 users with sensible browsing habits and no need for bundle features. Pick Avast Free Antivirus over Microsoft Defender if you are users wanting capable free tier and accepting post-FTC privacy reforms. On detection, AV-TEST 18/18 vs AV-Comp 2025 Gold Performance — verify current cycle on each vendor’s public report page. The decision is about price, bundle scope, and which protection model matches your household.
For full per-product details, see our individual deep-dive reviews: Microsoft Defender Antivirus review and Avast Free Antivirus review. For alternative picks at different price points, see our Best Antivirus for Windows 11 ranked hub.
