Microsoft Defender Antivirus
Microsoft Defender Antivirus: A free Windows antivirus with always-on protection and ransomware controls. Ranked #14 of 117 in Antivirus Software by our editors (7.9/10); pricing: Free plan; best for free Windows antivirus protection.
At a glance
- Editor score7.9 / 10
- PricingFree plan
- Best forFree Windows antivirus protection
- Free planYes
- Protection scopeAntivirus
- Founded1975 · Redmond, Washington, USA
- Facts checked20 Sep 2026
Where it wins
- Always-on protection with quick, full, custom, and offline scans
- Controlled folder access adds ransomware-focused protection
- SmartScreen and Windows Firewall integration extend Windows protection
Where it doesn't
- Works on Windows 10 and Windows 11 devices only
- Focused on antivirus rather than a broader standalone security suite
- Designed for Windows devices instead of multi-platform coverage
Our verdict on Microsoft Defender Antivirus
Microsoft Defender Antivirus is a free, real-time antivirus product built into Windows. It is designed for personal Windows 10 and Windows 11 devices, protecting against viruses, malware, spyware, and other threats without a separately priced subscription. Its core audience is people who want straightforward antivirus protection within the Windows environment, particularly those who do not need coverage beyond Windows.
The protection features cover everyday scanning and threat detection needs. Windows Security provides quick, full, custom, and offline scans, while cloud-delivered protection, automatic sample submission, and tamper protection support the product’s always-on approach. Controlled folder access adds a ransomware-focused safeguard, and Microsoft Defender SmartScreen warns about potentially malicious websites, apps, and downloads. Integration with Windows Firewall, Windows Security, SmartScreen, and OneDrive places the product within Microsoft’s broader Windows ecosystem rather than treating antivirus as a separate application.
Pricing is simple: Microsoft Defender Antivirus is included with Windows at no additional charge. There are no paid tiers described for this product, so buyers are choosing the included Windows protection rather than comparing subscription levels or add-on packages. That makes it a sensible fit for individuals seeking free antivirus coverage on Windows devices and who value built-in controls such as offline scanning, tamper protection, and Controlled folder access. It is less suitable for households or organizations that need antivirus coverage across platforms, since its supported platform scope is Windows 10 and Windows 11. Buyers seeking a separately priced, multi-platform product should consider an alternative with that coverage.
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Microsoft Defender Antivirus pricing
All 4 Microsoft Defender Antivirus plans and prices →
Microsoft Defender Antivirus fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Not verified |
| Protection scope | Antivirus |
| Device limit | Not verified |
| Supported platforms | Windows 10, Windows 11 |
| Ransomware protection | Yes |
| Parental controls | No |
| Password manager | No |
| Deployment | Desktop |
| Platforms | Windows |
| Support | Docs |
| Built for | Solo, Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 2 integrations: Windows Security, OneDrive |
| Pricing | Free plan (source) |
| Website | microsoft.com |
| Facts checked | 20 Sep 2026 |
Microsoft Defender Antivirus integrations
Microsoft Defender Antivirus lists 2 integrations on its own site.
- Windows Security
- OneDrive
Alternatives to Microsoft Defender Antivirus
- Microsoft Defender for BusinessA focused endpoint security subscription with EDR and centralized controls for small businesses.9.4
- Bitdefender GravityZone Small Business SecurityA paid endpoint security suite for small businesses needing layered protection and central control.9.3
- Bitdefender Total SecurityA broad security suite for families protecting PCs, Macs, phones, and tablets.9.2
See all Microsoft Defender Antivirus alternatives →
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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