Microsoft Defender Antivirus Review 2024: Should You Pay Extra for the Free Windows Antivirus?

The Microsoft Defender antivirus is included free with Windows, under the built-in security app Windows Security. This is a well-loved, easy-to-use, and free app that does a lot of the heavy lifting you need in terms of an antivirus.

If you want to extend this protection to other devices, you can get Microsoft Defender, which is another security app included in a Microsoft 365 subscription. With this subscription, you'll be able to take the Windows antivirus on to your iPhone, Android, or even Mac laptop. You'll also get additional features, like identity theft protection and the entire suite of Microsoft Office apps like Word and Excel.

We did a lot of research to figure out the differences between these two confusing products as well as figure out what exactly you’re paying for when purchasing Microsoft Defender. If you’re looking for the Microsoft Office suite, identity theft protection, parental controls, and other features, then you’ll want to check out everything offered within the Microsoft account subscription.

If you’re only looking for an antivirus on your Windows computer, what you get for free is a good option, but you won't be able to extend it to your other devices. For something more all-encompassing, you may want to check out some of the best antivirus available.

Microsoft Defender antivirus review at a glance

Price	$6.99–$9.99/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, Chrome, Safari, Firefox, Android, iOS
Extras	ID theft monitoring, VPN, cloud storage, Microsoft 365 apps
24/7 customer service	No
Learn more	Get Microsoft Defender with Microsoft 365

Our experience

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

Really, the only downside is the extremely confusingly named product lineup. The Microsoft Defender antivirus is part of both Microsoft Defender (paid service) and Windows Security (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 honestly 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 redirect you to the standard Windows Security app that you have access to 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 get 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. It even works on Mac devices to really spread the love around. Here's how it looked on our Android phone:

When it came to the actual scans, we were impressed with how fast it was able to scan our computer. It only took a few seconds for the quick scan, and the full scan took about 16 minutes.

We didn't notice much of a system slowdown when the scans were running, but our CPU utilization did reach 100%.

One pain point we have is that sometimes when Microsoft Defender does its automatic scan, we can feel the computer get sluggish but there's no indication why. It's only when opening up Task Manager that we can see the antimalware process eating up our CPU bandwidth that we can understand. And sure enough, we get a notification saying the scan was complete shortly after our computer returns to normal.

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 is just icing on top.

Who is Microsoft Defender antivirus best for?

• Recommended for anyone with a Windows computer that doesn't want to pay extra for antivirus

If you have a Windows computer and don't want to pay extra for an antivirus, it's a good-enough solution for most people who already practice safe online browsing. And if you need Microsoft Office apps, then might as well take advantage of the full Microsoft Defender suite.

But if you want to make sure everyone who uses your devices are safe, even the less tech-savvy ones like your young kids or grandparents, you may want to invest in a more all-encompassing antivirus option. The phishing protection in particular didn't work during our tests, and webcam protection is non-existent. So if you want those extra security features, you'll have to look elsewhere.

Microsoft Defender cost

The Microsoft Defender antivirus itself comes free with any Windows installation, but you can also purchase a Microsoft 365 plan to get access to the software on any of your devices. These subscriptions range from $6.99–$9.99/mo.

	Microsoft 365 Personal	Microsoft 365 Family
Monthly price	$6.99/mo	$9.99/mo
Number of devices protected	5	30
Number of people protected	1	6
Antivirus
Phishing protection
Firewall
Real-time protection
Ransomware protection
Parental controls
Identity theft protection
Cloud storage	1 TB	6 TB (1 TB per person)
Microsoft apps included	Yes — Word, Excel, PowerPoint, Outlook, OneDrive, Teams, Clipchamp, OneNote	Everything in the Personal plan, plus Family Safety

Microsoft Defender 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 call this feature a maybe.

Firewall

Microsoft Defender’s firewall feature is actually standard on Windows Security, so having Microsoft Defender doesn’t really enhance it in any way. We included this feature here so you have some information about it, but you have access to the firewall whether you purchase Microsoft 365 with Microsoft Defender or whether you choose to use the free Windows Security that comes with your computer.

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.

It’s the safest option to leave the domain and private network toggles on unless you run into issues downloading a new piece of software or another file that you know is good. 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.

If you aren’t sure a program is safe to whitelist, do an internet search for the exact app or program. Searching, “Is name of program safe to whitelist?” or “Is name of app malware?” lets you see others’ experiences with the program or app you’re trying to download.

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’re able to 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 get 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 individual 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:

• Word
• Excel
• PowerPoint
• OneNote
• OneDrive
• Ad-free Outlook
• Content library including photos, icons, fonts, videos, and audio
• Cloud storage
• Customer support
• Parental controls

Microsoft Defender 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 speed

• Result: Fast

Both Microsoft Defender antivirus scans we tried were extremely fast, taking less than 20 minutes to scan tens of thousands of files. We've seen other antivirus take over an hour to do a complete scan of the same amount of files, so this was nice to see.

Scan type	Time spent
Quick scan	21 seconds
Full scan	16 minutes and 54 seconds

EICAR test results

• Result: 2/3

One of the most useful tools available to test the effectiveness of antivirus software is the EICAR (European Institute for Computer Antivirus Research) test. 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 08/08/2024

Defender did a great job protecting against malicious file tests, catching both types of malicious downloads we threw at it: 

Unfortunately, it did not block the phishing page, even with the Microsoft Defender Browser Protection extension installed.

This meant it failed at phishing protection, but since there was no way to evaluate the phishing protection within an email client environment, we can’t say if it would block phishing emails. Remember, phishing attempts don’t always contain malware, sometimes they’re just tricky emails or web pages dedicated to duping you into volunteering up your private data.

AV-TEST results

• Result: 17.5/18

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 an almost perfect score.

Test type	Windows 11 score	macOS Monterey score	Android 11 score
Protection	5.5/6	N/A	N/A
Performance	6/6	N/A	N/A
Usability	6/6	N/A	N/A
Date	June 2024	N/A	N/A
Link to test	Link	N/A	N/A

It did have some points docked in the performance category, which is arguably the most important one. The score it received was 98.8%, which is a full point below the industry average of 99.8%. This was a slight decline from its test done in May of the same year, which scored 99.3%, so we hope it can turn it back around.

While this is arguing over small percentage points, when it comes to your safety online, that portion of a point can make all the difference.

The antivirus was also not included in tests on macOS or Android, which is disappointing. 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: Mid-range

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	98.8%	99.94%	13.8
Platform	N/A	Windows	Windows	Windows
Date	N/A	Feb - May 2024	March 2024	April 2024
Link	N/A	Link	Link	Link

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

For real-world protection, Microsoft came in seventh place with its score of 98.8%, which was remarkably similar to the score AV-TEST gave it for the same category. The first-place option for this category was a tie between Avast and AVG, both scoring a perfect 100%.

Malware protection was much the same story, with Microsoft coming in sixth place and categorized as having "many false positives" with a total of 18. The winners of this round include Kaspersky and Trend Micro, both of which only had 3 false positives.

Finally, performance saw an even worse outcome for Microsoft, coming in 12th out of 16. It was determined to impact system performance by a total of 13.8 points, compared to the first place software (McAfee) only affecting it by 2.8 points.

SE Labs results

• Result: 100%

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

Test type	Home Anti-Malware Protection
Total accuracy rating	100%
Date	2024 Q2
Link	Link

This time, Microsoft Defender tied for first place, getting a remarkable 100% accuracy score in all three categories: protection accuracy, legitimate accuracy, and total accuracy.

Microsoft Defender compatibility

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 is compatible with:

• Windows
• Mac
• iOS devices like iPhone and iPad
• Android devices like phones and tablets

Microsoft Defender customer support

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 rep via chat to get clarification about the differences between the multiple Microsoft products. He was extremely helpful, though clearly was copy-pasting off a script.

Still, it was a quick and easy process overall.

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.

Microsoft Defender FAQs

Bottom line: Is Microsoft Defender good?

Yes, the Microsoft Defender antivirus is a good security tool for people who already have good online security knowledge. But if you want to get closer to 100% protection, you'll want to look elsewhere. It did not score well on some third-party tests, and failed our phishing test.

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 beef it up with Microsoft Defender, just make sure you have antivirus protection for Windows enabled whenever you’re online.