If you are on this sub even semi frequently, you have probably seen many questions like this. The comments on these posts are people arguing and attacking each other. My personal opinion is that it isn't that good. But, I decided to do my own tests.

I tested windows defender against my 2 personal favourite free AVs. Kaspersky and Bitdefender.

I tested them on a VM using a folder of 300+ malware samples collected off of malware bazzare and other websites, and used an automated script to execute all of the malware in the file 1 by 1 and keep track of the detection rates.

First test, was just a right click scan on the malware folder. (I manually calculated Detection rates here)

Kaspersky won with a detection rate of 98%

Bitdefender was 2nd with 97.7%

And windows defender with 96.5%

Kaspersky and Bitdefender deleted the files from quarantine easily. No problems. Defender on the other hand, was pretty bad. The UI was super buggy and kept flashing as it updated. After leaving it for close to 20 minutes, it finally caught up. After selecting remove, it took a very long time to finish. When it was done, it failed to remove over 10 samples. The malware removal is below par

Next, the real-time protection test. As I explained before, an automated script executes all malware samples 1 by 1 and calculates the detection rates. All AVs were untouched (Other than database updates) and ran with the default settings.

Kaspersky and Bitdefender drew with a clean sheet. 100% of the malware was detected and dealt with.

And surprisingly, Windows defender actually failed. A ransomware sample managed to execute. WD did end up killing it, but it was too late, all of the test files were encrypted. 2 other malware samples executed and weren't detected.

A second attempt saw windows defender block the same Ransomware fast enough, that the files actually survived. The same 2 malware samples executed.

Next, I disabled RTP to test their behavioural analysis. In this one, I manually executed 50 files as I felt this was a slightly more real world test.

Bitdefender won, it blocked 43 files upon execution, and and another 2 samples after about a minute. 45/50

Kaspersky was right behind with 43/50 files blocked. No other samples were blocked.

Windows defender blocked, 38/50 files and blocked 1 a few minutes after execution.

Overall, Kaspersky is the strongest out of the 3. Bitdefender is also a very strong option, you can't go wrong with either. (After thinking for a bit, Bitdefender and Kaspersky probably drew.)

And then windows defender. Yes, it Should be good enough for "Most people". You aren't likely to be executing 300+ malware samples in your day to day use. But, I don't understand why you choose defender when the other 2 AVs are 100% free, and overall much stronger. They take about 10 minutes to install at most, so the convenience argument for WD isn't as big as its made out to be.

You can make your own choices, but I just wanted to do some tests to see what was true, and what wasn't.

Basically the title. From everything I read online it sounds like Defender is adequate as comprehensive protection for most folks. Obviously, if you're clicking links willy nilly or need more advanced protection, you probably need other tools - but for the casual, home user do you all feel Defender is "enough".

Mostly asking for my Mom. I've spent my career in tech so personally I'm to the point I feel it's enough for my home PC. But Mom's from a generation that is scared of everything and has a hard time taking me at just my word - so any links to reports or recommendations would be appreciated. I've done a fair amount of searching, but haven't come across anything I think would make sense to her.

Thanks!

UPDATE: Thank you everyone for the replies. I do work in tech and definitely have coached her, informed her and shamed her (lol) into safe habits. She's older but definitely logical and detail oriented so she gets it. It's more a somewhat outdated perspective that you "need" something extra on top of Windows (she was a Norton user "back in the day"). I really appreciate all the feedback and sharing with her the responses I got here have made her a lot more comfortable just relying on Defender.