Microsoft Defender Antivirus Review 2026: How Well Does This Free Program Perform?

If all you need is basic antivirus protection for your Windows device, then Microsoft Defender is a great option. Microsoft Defender is installed on all devices with Windows 10 and Windows 11, so it's completely free. It has also scored perfect or near-perfect test scores with third parties like AV-TEST, AV-Comparatives, and SE Labs.

For device protection across operating systems, you'll need to purchase a Microsoft 365 subscription. This can get expensive if you only need an antivirus. Microsoft Defender also lacks web protection, so it's not the most comprehensive antivirus. 

In this Microsoft Defender review, we'll go over its testing performance, features, and more, so you can decide if Microsoft Defender is the best antivirus for you.

At a glance

Price	Free for Windows users, otherwise $1.99–$16.67/mo
Free plan	No
# of devices protected	5 - 30
Malware scans	Manual and scheduled
Real-time protection	Yes
EICAR test results	2/3
Firewall	Yes
Phishing protection	Yes
Compatibility	Windows, macOS, Linux, Android, iOS
Extras	Identity theft protection, parental controls, cloud storage, Microsoft 365 apps
24/7 customer service	No
Learn more	Get Microsoft Defender with Microsoft 365

Star rating summary

We last tested Microsoft Defender in Q1 2026.

Our experience

The Windows antivirus is a tried-and-true classic for us. We've consistently been impressed with the level of security Microsoft can provide without charging extra. 

Really, the only downside is the extremely confusing product naming lineup. The Microsoft Defender antivirus is part of both Microsoft Defender (the paid service) and Windows Security (a built-in security app).

To make matters worse, Windows Security used to be called Windows Defender Security, adding to the confusing lineup of names. It almost seems like a deliberate attempt to confuse people into getting a Microsoft 365 subscription, but we just hope they don't put the antivirus behind the paywall in the future.

Just to make sure we weren't missing much in terms of antivirus protection by not having Microsoft Defender, we bought a subscription to Microsoft 365 to try it out. Sure enough, all the device protection options in the app redirected us to the standard Windows Security app, which is available for free.

That's not to say there isn't value in having a subscription. On top of all the extras you get, you can also extend your Microsoft Defender antivirus protection to up to five devices, which means you can protect your phones with the same service you already trust. That includes macOS, Android, and Linux. Here's how it looked on our Android phone:

When it came to the actual scans, Microsoft Defender Antivirus can be slower than other antivirus programs in our experience. The Quick Scan took about five minutes and the Full Scan took about 30 minutes. We're used to quick scans taking one or two minutes and full scans taking 10 to 20 minutes. 

In terms of the extra features you get, we found them on par with its competitors, especially the identity theft protection software, which can get pretty pricey as a standalone product. Getting access to the Microsoft Office apps is a non-negotiable for some people, so any extras you can get are just icing on top.

Microsoft Defender antivirus prices and plans

The Microsoft Defender antivirus itself comes free with any Windows installation. You can also purchase a Microsoft 365 plan to get access to the software on any of your devices. These subscriptions range from $1.99–$16.67/mo.

	Microsoft 365 Basic	Microsoft 365 Personal	Microsoft 365 Family	Microsoft 365 Premium
Annual price	$19.99/yr	$99.99/yr	$129.99/yr	$199.99/yr
Number of devices protected	1	5	30	30
Number of people protected	1	1	6	6
Antivirus
Phishing protection
Firewall
Real-time protection
Ransomware protection
Identity theft protection
Cloud storage	100 GB	1 TB	6 TB (1 TB per person)	6 TB (1 TB per person)
Copilot features		Select features	Select features	All features
Microsoft apps included	Outlook, OneDrive	Word, Excel, PowerPoint, Outlook, OneDrive, Teams, Clipchamp, OneNote, Microsoft Designer	Word, Excel, PowerPoint, Outlook, OneDrive, Teams, Clipchamp, OneNote, Microsoft Designer	Word, Excel, PowerPoint, Outlook, OneDrive, Teams, Clipchamp, OneNote, Microsoft Designer
Learn more	View plan	View plan	View plan	View plan

Heads up: College students can purchase Microsoft 365 Individual for $2.99/mo with a valid college email address all year long.

Microsoft Defender antivirus features

Microsoft Defender provides enhancements for the free pre-installed Windows Security antivirus feature that comes with Windows 10 and Windows 11.

Most of the following features come with the free Windows Security antivirus tool — Microsoft Defender either adds additional functionality or enhanced security. But Microsoft Defender also gives you identity theft protection, which isn’t included in Windows Security.

Malware and antivirus scan

The Microsoft Defender antivirus, included for free with the built-in Windows Security app, includes a feature that automatically monitors your activity online to scan for viruses and provide malware protection.

The scanning features are easy to use and allow you to scan your entire drive or create custom scans. Custom scans allow you to get granular by scanning an external drive like a USB drive or scanning your downloads folder on your computer.

Phishing protection

Microsoft Defender’s phishing protection is more of a hands-off kind of tool. The permissions are set within the security settings, and unless you alter them, they look for credentials that are consistent with phishing activities. 

What that means is the software looks at a website or email and says, “Hmm, this looks a lot like this other thing that was a phishing scam. Let’s flag it.” Because the permissions are already set, you won’t really need to do anything. 

If you feel confident in your ability to add or delete permissions, you can alter how Defender identifies phishing attempts. We caution against that, though, unless you’re a professional who is used to configuring permissions. 

Otherwise, the software learns from the world around it and protects you in various situations.

In our time testing the product, we weren't able to get it to trigger the phishing protection, even when using tools designed to do so. So we consider this feature unreliable.

Firewall and network protection

Microsoft Defender’s firewall feature is actually standard on the free Windows Security, so having Microsoft Defender doesn’t really enhance it in any way. 

There are three separate firewall configurations that protect your domain network, private network, and public network. These are toggled on, but you have the option to change them depending on what you need.

You should leave the domain and private network toggles on unless you run into issues downloading a new piece of software or file that you know is safe. You should definitely leave the public network toggle on, especially if you’re on public Wi-Fi.

If you do find the firewall interfering with legitimate programs, there are tutorials and whitelisting options available right in the dashboard to help you grant access. Make sure you’re 100% confident the program you want to whitelist is safe, though, because you’ll be bypassing security to allow it to run.

Real-time protection

The real-time protection features are located in the Virus & threat protection settings. You can toggle it off and on, but we recommend keeping it on. Windows Security can identify malware and stop it from executing or installing on your computer, tablet, or phone.

While the option to toggle off is available, real-time protection turns itself back on automatically after a time. If you accidentally forget to toggle back on, it will eventually re-activate to keep you protected.

It’s best to leave real-time protection enabled all the time. You may think you’re safe just because you don’t open suspicious email attachments, but malware, unfortunately, can be anywhere. It can even infect your device by simply clicking on a website. 

Real-time protection means you have an antivirus guarding your every move.

Ransomware protection

Windows Security offers you ransomware protection with its virus protection but also in the form of backups and recovery options.

You can create a backup of your files and folders via OneDrive, and your data is stored there in the event of a ransomware infection. Instead of having to pay to unlock your files and folders, OneDrive backup allows you to wipe your device clean, get rid of the ransomware, and reinstall with the option to recover your files.

The prevention part of Windows Security ransomware protection is through Controlled folder access. This portion of the ransomware protection feature recognizes applications that may be hostile to your environment, like ransomware, and protects your files from being changed by these potentially hostile applications. 

Good preventative measures like these can save you by helping to stop ransomware attacks before they happen.

Anti-fraud protection

The anti-fraud protection is the best reason to buy Microsoft Defender. While Defender does enhance the security tools of Windows Security, it also offers identity theft protection that isn’t included in Windows Security.

If you purchase the Microsoft 365 Family plan, you’ll receive protection for up to six people. If you purchase the Personal plan, you’ll only have protection for yourself. 

Either way, you receive identity monitoring, web monitoring, identity theft insurance, and remediation experts if you do end up in an identity theft situation. Microsoft Defender is partnered with Experian to offer these services to customers.

Just note that the identity theft protection feature is only available in the U.S. at this time.

Bonus features

There are plenty of bonus features offered with a Microsoft 365 subscription. Some of the features include:

• Microsoft Word
• Microsoft Excel
• Microsoft PowerPoint
• OneNote
• OneDrive
• Ad-free Outlook.com
• Cloud storage
• Parental controls
• Copilot

Microsoft Defender antivirus test results

When it comes to your security, we don't just take a company's word for it. We put antivirus software to the test and make sure it actually does what it claims to.

These tests include seeing how long scans take and using tools designed to test your antivirus software in real time. We also rely on third-party test results, which allows us to see a much more wide-reaching comparative view of the product.

Scan efficiency

• Result: Found all EICAR files with a Quick Scan

First, we evaluate if the antivirus programs we review can detect malware that was on our device prior to the antivirus download. We placed EICAR (European Institute for Computer Antivirus Research) files on our desktop, downloads folder, and screenshots folder. 

Microsoft Defender detected all three files with just a Quick Scan. Almost all the antivirus programs we tested miss the file on our desktop, but Microsoft had no issues with this.

Note that Microsoft Defender is slower than most antivirus programs, but your scan speeds are affected by several factors including the number of files on your device and the computer resources being used by other programs.

	Quick Scan	Full Scan
Time spent	5 minutes, 26 seconds	30 minutes, 19 seconds
# of files scanned	76,008 files	911,447 files
Did it find EICAR files?	Yes, 3/3	-

EICAR test results

• Result: 2/3

EICAR files and websites are some of the most useful tools for testing the effectiveness of antivirus software. It provides malware and phishing tests to see how antivirus software stacks up.

The tests run by EICAR don’t contain actual malicious files, but they behave like malicious files. If your antivirus software is working properly, you shouldn’t be able to download any of the executables or read the phishing page.

Test	Microsoft Defender score
Malware detection	Pass
Drive-by malware downloads	Pass
Phishing pages detection	Fail

Test results as of Q1 2026.

Microsoft Defender did a great job protecting against malicious file tests, catching both types of malicious downloads: 

Unfortunately, it didn't block the phishing page, even with the Microsoft Defender Browser Protection extension installed.

This meant it failed to provide effective phishing protection on the web, but we don't test to evaluate the phishing protection within an email client environment. Remember, phishing attempts don’t always contain malware; sometimes they’re just tricky emails or web pages dedicated to duping you into volunteering your private data.

AV-TEST results

• Result: 17/18

AV-TEST is one of the industry’s leading and most trusted third-party testing sites. It puts antivirus software through rigorous testing to make sure nothing gets through. Windows Security did a pretty good job, receiving a perfect score during the latest round of testing.

Test type	Windows score	macOS score	Android score
Protection	6/6	N/A	N/A
Performance	6/6	N/A	N/A
Usability	6/6	N/A	N/A
Total	18/18	N/A	N/A
Date	December 2025	N/A	N/A
Link to test	Link	N/A	N/A

Microsoft Defender aced the protection, performance, and usability tests, matching or beating the industry average in every test. For instance, the industry averaged one false positive of legitimate software during a system scan, but Microsoft Defender detected none in November and December.

The antivirus was not included in tests on macOS or Android, which makes sense since it's primarily for Windows. This isn't necessarily a knock against it, though, since third-party tests can get pricey and obviously Windows testing would be the priority.

AV-Comparatives test results

• Result: Falls in the middle of the pack for protection and performance

Like AV-TEST, AV-Comparatives is a leading option when it comes to testing antivirus software, putting each one through identical rigorous tests to find the real best of the best.

Test type	Mobile security	Real-world protection	Malware protection	Performance impact (Lower is better)
Score	N/A	99.1%	100%	13.5
Platform	N/A	Windows	Windows	Windows
Date	N/A	July - October 2025	September 2025	September 2025
Link	N/A	Link	Link	Link

When it comes to protection, Microsoft Defender was squarely in the second group of antivirus programs tested. These are the ones that performed okay, but were outshined by other options like Norton and McAfee.

For real-world protection, Microsoft Defender came in fourth place alongside Bitdefender and F-Secure. The highest protection rate was 100%, which was scored by Avast, AVG, and Norton.

However, Microsoft Defender came in first place in the latest malware protection test. It tied with ESET, G Data, and McAfee.

Finally, performance saw an even worse outcome for Microsoft, coming in ninth out of 18. Compare Microsoft Defender's performance impact score with Kaspersky, which came in first place with a 3.0 score.

SE Labs results

• Result: 100% total accuracy rating

Finally, SE Labs performs quarterly antivirus tests at both the consumer and enterprise level, releasing detailed reports.

Test type	Home Anti-Malware Protection
Protection accuracy rating	100%
Legitimate accuracy rating	100%
Total accuracy rating	100%
Date	2025 Q4
Link	Link

Microsoft Defender received a perfect protection accuracy rating and legitimate accuracy rating, which round out to its 100% total accuracy rating.

Microsoft Defender antivirus compatibility

	Microsoft Defender compatibility
Windows
macOS
Android
iOS
Browser extensions	Yes — Google Chrome

While the Windows Security app only comes pre-installed with Windows licenses, subscribing to Microsoft 365 gives you access to Microsoft Defender — which is compatible across all your devices.

Microsoft Defender antivirus customer support

Support type	Microsoft Defender
Email or live chat
Phone
Online guides or forums

Customer support is available via chat or phone. You get access to the live chat for free, but only Microsoft 365 subscribers can request a callback for phone support. There are also a wealth of guides and forum posts to dive into.

We spoke with a customer service representative via chat to get clarification about the differences between the multiple Microsoft products. The representative was extremely helpful, though clearly was copy-pasting off a script.

Still, it was a quick and easy process overall.

Microsoft Defender user reviews

• Apple App Store rating: 4.7
• Google Play Store rating: 4.4
• Trustpilot rating: 1.2

Microsoft Defender has largely positive reviews on both mobile app stores. On iOS, reviewers praise Microsoft Defender's wide range of security tools, although some reviews call out the discontinued VPN. On Android, reviewers mention that the product works well, though there's some disappointment that it's not free. 

However, almost all of Microsoft's Trustpilot ratings are one star. Most reviewers mention how difficult it can be to get in touch with support, especially human agents rather than chatbots. They also feel the website has a poor user interface. 

Top alternatives

If you’re not loving all the features that come with Microsoft 365 and Microsoft Defender, there are other options to choose from. These are some of the best antivirus programs on the market.

Bottom line: Is Microsoft Defender antivirus good?

Yes, the Microsoft Defender antivirus is a good free security tool if you already have Windows. But if you want to get closer to 100% protection, you'll want to look elsewhere as it doesn't provide reliable phishing protection. 

And don't be confused into getting the Microsoft 365 subscription just to access an antivirus on your Windows computer. The antivirus itself, Microsoft Defender antivirus, comes built-in with the Windows Security app. 

The Microsoft Defender app is another app that also includes the antivirus for other devices, plus some extras. But you don't need it if you're looking for the free version.

Its additional identity protection, as well as the Microsoft Office tools, increase its value. Whether you decide to go with the included Windows Security or enhance it with Microsoft Defender, just make sure you have antivirus protection for Windows enabled whenever you’re online.

Learn how Microsoft Defender compares to other top antivirus programs:

• Microsoft Defender vs. Norton
• Microsoft Defender vs. Avast
• Microsoft Defender vs. Bitdefender
• Microsoft Defender vs. TotalAV
• Microsoft Defender vs. Aura Antivirus

Microsoft Defender antivirus FAQs