Should you choose Windows Defender over Avast Free Antivirus? Both are free. One is developed by Microsoft and built-in within Windows. The other one is developed by leading security company – Avast. Let’s compare them together.
Detection rates
Winner: Avast Free Antivirus
The most important factor of any computer protection is detection rate. If your antivirus doesn’t detect malware in files, you might get your PC infected. The lower missed samples can antivirus achieve, the better protection it provides. If we compare Windows Defender vs Avast Free Antivirus detection rate, Avast Free Antivirus is obvious winner. According independent testing organization AV-comparatives Avast missed only 0.1% of all samples, which is one of the best result among all antivirus developers. Windows Defender on the other side end up worst with 1% of missed samples.

Source: Anti-Virus Comparative – File detection test (September 2016)
Additional Features
Winner: Avast Free Antivirus
Antivirus programs usually offer lot of additional features to protect user against online threats. The core function will be always scanning and protection against malware. In this section we will have a look at additional features which Windows Defender and Avast Free Antivirus offers on Windows 10.
Feature |
Avast Free Antivirus |
Windows Defender |
Antivirus & Anti-malware (Core function) |
Yes |
Yes |
Mail protection |
Yes |
Yes |
Web-traffic scanning |
Yes |
No |
Browser cleanup |
Yes |
No |
Password manager |
Yes | No |
Secure browser |
Yes |
No |
Silent mode |
Yes |
No |
Clear winner in this category is also Avast Free Antivirus 2016 for Windows 10. Windows Defender doesn’t offer any features which would support core function of antivirus software. Avast Free Antivirus on the other side offers a lot of free features to enhance protection of user’s Windows 10 PC.
User interface
Winner: Avast Free Antivirus
If you compare user interface of Avast and Windows Defender, Avast offers an easier navigation and more organized interface compare to Defender. Users have a chance to access smart scan (feature of Avast Free Antivirus) directly from main window. On Windows Defender you can launch full-scan directly from main screen as well.
You will probably have no problems to navigate in user interface of both antivirus programs however Avast Free Antivirus offers much cleaner and organized look. Compare it yourself.
Advertising
Winner: Windows Defender
Windows defender is free of any advertising as it is antivirus built-in into your Windows 10 operating system. As Avast is a 3rd party software, it is using advertising to convince you to upgrade to higher protection level. This can be obtrusive for some users however this is standard among most of the 3rd party antivirus vendors.
Summary
Overall winner of this battle is definitely Avast Free Antivirus which offers better detection rates, more features and cleaner user interface compare to Windows Defender. If you don’t mind advertising integrated into Avast, it is a definite choice against Windows Defender.