Windows Defender

Microsoft Home Antimalware (primary)Enterprise Antimalware Free Antimalware Small Business Antimalware Compare with others in Home Antimalware

Product

Windows Defender, now called Microsoft Defender Antivirus, is the anti-malware and antivirus protection built into Windows 10, Windows 11 and Windows Server. Microsoft Defender Antivirus is a major component of your next-generation protection in Microsoft Defender for Endpoint. Microsoft Defender Antivirus is built into Windows, and it works with Microsoft Defender for Endpoint to provide protection on your device and in the cloud. You can use one of several methods, such as the Windows Security app or Windows PowerShell, to check the state of Microsoft Defender Antivirus on your device. Among the capabilities recorded for it are behavioral detection, cloud-assisted scanning, heuristic detection and malware detection.

Current Version: 6.1
Product Page: learn.microsoft.com/…/microsoft-d…
Market: ConsumerEnterpriseSMB
Licence: Free
Price: Free
Record Created: 2026-08-20
Last Updated: 2026-10-21

Vendor

Microsoft is the largest security vendor in this index by installed base, and almost none of that was bought deliberately: Microsoft Defender Antivirus is built into Windows and switched on by default, so it protects any machine whose owner has not installed something else. That changes how its results should be read — it is the baseline every other product in this index is implicitly compared against. The paid products are a different thing from the built-in one. Microsoft Defender for Endpoint adds detection and response, threat and vulnerability management and central policy to the same engine; Microsoft Defender for Business is the smaller-organisation edition; Microsoft Defender XDR correlates signals across endpoints, identity, email and cloud apps; and Microsoft Sentinel is the SIEM above them. Microsoft Defender for Individuals, included with Microsoft 365, is the consumer application. Microsoft enters the public test cycles regularly, and its results are among the most consistently available in this index — useful, because for many readers the real question is not which product is best in the abstract but whether a paid product beats the one already installed. Vendor page →

Website: microsoft.com
Country: United States
Headquarters: Redmond, United States
Year Established: 1975
Customers: 1.6M organisations
Users: 1.4B devices protected
Revenue: $331.8B (2026)

Platforms

Windows	native
Windows Server	native

Target Market

Consumer primaryEnterprise secondarySMB secondary

Capabilities

Pricing

Plan	Licence	Priced per	Billed	Price
Summary	Free	not stated	no recurring charge	Free

Versions

6.1Windows

The newest release each source names per platform, not every release the vendor has shipped. A release date is shown only where one is recorded.

Independent Tests

At a glance — latest result per lab test

AV-Comparatives Real-World Protection TestAdvanced+

Tested: Windows2026-06-15lab report ↗

AV-Comparatives Malware Protection TestStandard

Tested: Windows2026-10-15lab report ↗

AV-Comparatives Performance TestAdvanced

Tested: Windows2026-10-20lab report ↗

AV-TEST Antivirus Test

Tested: Windowslab report ↗

SE Labs Home Anti-Malware ProtectionAAA

2026-06-30lab report ↗

Each bar is one lab’s own figure on that lab’s own scale. Labs test different models at different times, so the figures are not combined into one score.

All results

AV-Comparatives Real-World Protection TestAV-Comparatives Real-World Protection Test — February–May 20262026-06-15

Advanced+Protection Rate: 99%False Positives: 0

AV-Comparatives Real-World Protection TestAV-Comparatives Real-World Protection Test — July–October 20252025-11-17

Advanced+Protection Rate: 99.1%

AV-Comparatives Malware Protection TestAV-Comparatives Malware Protection Test — March 20262026-04-15

Advanced+Offline Detection Rate: 89.2%Online Detection Rate: 98.1%Online Protection Rate: 99.93%False Positives: 3

AV-Comparatives Malware Protection TestAV-Comparatives Malware Protection Test — September 20252025-10-15

StandardOffline Detection Rate: 88.4%Online Detection Rate: 97.9%Online Protection Rate: 100%False Positives: 27

AV-Comparatives Malware Protection TestAV-Comparatives Malware Protection Test — September 20262026-10-15

StandardOffline Detection Rate: 82.2%Online Detection Rate: 95.5%Online Protection Rate: 99.89%False Positives: 28

AV-Comparatives Performance TestAV-Comparatives Performance Test — April 20262026-04-22

AdvancedImpact Score: 12.9AV-Comparatives Score: 80

AV-Comparatives Performance TestAV-Comparatives Performance Test — September 20252025-10-15

AdvancedImpact Score: 13.5AV-Comparatives Score: 80

AV-Comparatives Performance TestAntivirus Performance Test September 20262026-10-20

AdvancedImpact Score: 13.5AV-Comparatives Score: 80

AV-TEST Antivirus TestTest antivirus software for Windows 11 - June 2026

Protection: 6Performance: 5.5Usability: 6

AV-TEST Antivirus TestTest antivirus software for Windows 11 - August 2026

Protection: 6Performance: 5.5Usability: 6

SE Labs Home Anti-Malware ProtectionHome Anti-Malware 2026 Q2

AAAOverall 98Protection Accuracy: 95%Legitimate Accuracy: 100%Total Accuracy Rating: 98%

SE Labs Home Anti-Malware ProtectionHome Anti-Malware 2026 Q1

AAAOverall 100Protection Accuracy: 100%Legitimate Accuracy: 100%Total Accuracy Rating: 100%

Certifications

OESIS Framework SupportSupported1 activeSupported

OPSWAT Certified Security ApplicationPlatinum1 activePlatinum

Change History

This record was created 2026-08-20. Everything below is what has changed since.

2026-10-21Test result addedNew AV-Comparatives Performance Test result: Advancedevidence
2026-10-15Test result addedNew AV-Comparatives Malware Protection Test result: Standardevidence
2026-10-14Product updatedListed in Enterprise Antimalwareevidence
2026-10-14Product updatedListed in Small Business Antimalwareevidence
2026-10-10Product updatedSold to: Consumerevidence
2026-10-09Test result addedNew AV-Comparatives Performance Test result: Advancedevidence
2026-10-09Test result addedNew AV-Comparatives Performance Test result: Advancedevidence
2026-10-09Test result addedNew AV-Comparatives Malware Protection Test result: Standardevidence
2026-10-09Test result addedNew AV-Comparatives Malware Protection Test result: Advanced+evidence
2026-09-30Test result addedNew SE Labs Home Anti-Malware Protection result: AAAevidence
2026-09-30Test result addedNew SE Labs Home Anti-Malware Protection result: AAAevidence
2026-09-30Test result addedNew AV-TEST Antivirus Test resultevidence
2026-09-28Test result addedNew AV-Comparatives Real-World Protection Test result: Advanced+evidence
2026-09-28Test result addedNew AV-Comparatives Real-World Protection Test result: Advanced+evidence
2026-09-23Capability addedCloud-Assisted Scanning: built inevidence
2026-09-23Capability addedBehavioral Detection: built inevidence
2026-09-23Capability addedHeuristic Detection: built inevidence
2026-09-23Platform addedRuns on Windows Serverevidence
2026-09-22Product updatedListed in Enterprise Antimalwareevidence
2026-09-22Product updatedListed in Small Business Antimalwareevidence
2026-09-22Product updatedListed in Free Antimalwareevidence
2026-09-22Product updatedListed in Home Antimalwareevidence
2026-09-20Test result addedNew AV-Comparatives Real-World Protection Test resultevidence
2026-09-20Test result addedNew AV-Comparatives Real-World Protection Test resultevidence
2026-09-19Product updatedAlso sold to: SMBevidence
2026-09-18Test result addedNew AV-TEST Antivirus Test resultevidence
2026-09-09New versionNew version: 6.1 (Windows)evidence
2026-08-26Test result addedNew AV-Comparatives Real-World Protection Test resultevidence
2026-08-26Test result addedNew AV-Comparatives Real-World Protection Test resultevidence
2026-08-25Test result addedNew AV-Comparatives Real-World Protection Test resultevidence
2026-08-25Test result addedNew AV-Comparatives Real-World Protection Test resultevidence
2026-08-20Certification addedCertified: OESIS Framework Support (Supported)evidence
2026-08-20Capability addedMalware Detection: built inevidence
2026-08-20Pricing plan addedPrice: freeevidence
2026-08-20Product updatedAlso sold to: Enterpriseevidence
2026-08-20Product updatedAlso sold to: Consumerevidence
2026-08-20New versionNew version: 6.1evidence
2026-08-20Platform addedRuns on Windowsevidence
2026-08-20Certification addedCertified: OPSWAT Certified Security Application (Platinum)evidence
2026-08-20Product createdNew product listedevidence

Something wrong? Suggest a correction →

Malware Detectionkey	native
Ransomware Protectionkey	Not known
Behavioral Detectionkey	native
Web Protectionkey	Not known
Email Protection	Not known
Host Firewall	Not known
Sandbox Analysis	Not known
Cloud-Assisted Scanning	native
Heuristic Detection	native
Device Control	Not known
Vulnerability Shielding	Not known
Central Management Console	Not known