Best Free Antivirus Software

Other Language?
  Read this article in Spanish
  Read this article in Chinese
In a Hurry?
  Go straight to the Quick Selection Guide

Antivirus software provides an essential layer of protection from viruses, trojans, worms, spyware, adware, dialers, keyloggers, and rootkits. Don't let the name antivirus confuse you. These days every good antivirus has good detection rates for all forms of malware, not just viruses. The term malware includes viruses, trojans, worms, spyware, adware, dialers, keyloggers, rootkits, and any other software which performs malicious activities on a computer.


Sadly, the amount of malware currently in circulation is so large that no antivirus could possibly detect all of it. Despite vendor's claims, no single antivirus solution can detect nearly all new malware. There are some products out there, including some in this review, which include technologies which are able to adequately protect a computer, but any product which relies mainly on detection is statistically doomed to fail at some time. Also, using more than one real-time antivirus at the same time uses much more system resources, can cause system errors, and can even reduce protection. For my advice on how to compensate for these weakness of antivirus products, to a large extent, please see my other article about How to Stay Safe While Online. Having a good antivirus product does go a large way towards adequately protecting your computer, but in this day I would highly recommend that you add additional layers to your security.


Below I have reviewed some of the most effective Free Antivirus products currently on the market. In order to make this review more unbiased, although of course my own intuition and experience does affect my judgment as well, I came up with a particular methodology for comparing these products. This methodology is described in the following section.

Methodology For Comparing Products

The main motivation behind why I came up with this particular methodology for this review is that I value system protection against real world threats above all other categories by which an antivirus is commonly judged. It does not matter to me whether an antivirus protects the user by detecting malware, blocking dangerous sites, behavioral analysis, sandboxing, or any other approach. The most important thing is that at the end of the day your system is safe from infection. Thus, that is the attitude I have taken towards reviewing these products.


Therefore, I found Antivirus testing organizations which claim to test products against situations which resemble real-world situations. I narrowed these down by further requiring that the organizations have a relatively long record of producing good, seemingly unbiased, results. The organizations I ended up with, and therefore used for this review, are:



Dennis Technology Labs

From here I looked at all tests ranging to the beginning of 2013. However, if there were more than three tests within that range I used only the most recent three. Also, if given the choice between results from different operating systems, I chose that for the most popular operating system. At the moment Windows 7 is the most popular operating system.

Also, I only considered results if it was specifically the Free Version which was tested. This is because the results for the Paid Version of the products in this review, with the exception of Comodo Antivirus, are often quite different from those for the Free versions.

In addition, I did not count it against any of the products if they were not tested by multiple organizations. As long as they were tested by at least one, within the above-mentioned period, they were considered. This criteria was chosen because there are many reasons to choose not to participate in a test. Thus, it should not be held against the product if they were not tested by multiple agencies. However, if they were not tested by any, this makes it impossible to compare them in an unbiased fashion.


Once this data was collected, I then looked at the overall results for the Free Antivirus products discussed in this review, and ordered them mainly according to the quantitative results. However, my own knowledge of the products, and the reviews and experiences of others, were also considered. The results are presented and discussed below.

Discussion And Comparison

Comodo Antivirus is my top pick for advanced users or for Intermediate users who are okay with an antivirus software which will occasionally ask them for input. However, if you do not fall into those categories, or for any other reason find it to not be a good fit for you, then you will likely find my next pick suitable. Also, for those who prefer a complete solution, there is always Comodo Internet Security, which is also free and includes a firewall in addition to all other components which already come with Comodo Antivirus.

The reason I made this my top pick for advanced users or users who are okay with a somewhat talkative antivirus software, is because it is the only product which I feel confident saying that it will protect you against nearly 100% of real-world threats. I have a lot of experience with this product. I am a volunteer moderator on the Comodo forums and have been using it for a long time. I know this product very well, and am entirely confident in its ability to protect.

Comodo Antivirus uses the cloud to facilitate the detection of the most recent malware, as do many other Free Antiviruses reviewed in this article. However, Comodo also incorporates a Behavioral Blocker, which will automatically sandbox all software which it does not know for sure is safe. Thus, the user is protected from nearly all malware, which will either be detected by the antivirus component or sandboxed by the Behavioral Blocker. It will also analyze unknown applications for suspicious behavior, and alert the user accordingly.

However, as mentioned previously, users who do not want a somewhat talkative antivirus should continue to my next pick. Also, by default Comodo Antivirus has small advertisements (which can be disabled as shown here). Also, during installation users should be sure to click the Customize Installer option, which is near the bottom-left of the installation window. This will allow them to uncheck additional software, which the installer will automatically install with Comodo Antivirus unless unchecked. This software is not dangerous and includes a browser, and ad-blocking addon, and an optional paid service which would allow Comodo technicians to assist you with any computer problems you have. These, and a later option to change your homepage to support Comodo, can safely be unchecked during installation. Even with this extra hassle, this software is still my top pick, but I do wish they made the process simpler.


Avast! Free AntivirusAvast! Free Antivirus is has very good protection rates. Avast has many different protection shields, boot-time scanning, a behavioral blocker, an internet site ratings plugin, script malware protection, and access to cloud-based protection. It's arguable whether their ratings plugin offers comparable levels to WOT, but the script malware protection can prevent certain browser exploits, a feature not available in any of the other free AV's reviewed.

Avast is also relatively light on resources. However, do note that Avast requires a free registration to function after 30 days, and the default installation installs the Chrome browser unless you uncheck it. Also, note that the OpenCandy advertising component is integrated into the Software Updater tool in Avast. More information about OpenCandy can be read here. Thus, if a user selects this option during the install they will end up with OpenCandy on their computer. Please be very careful about this option if you choose to install 


Panda Cloud AntivirusPanda Cloud Antivirus is another excellent choice for average users, who may find both Comodo Antivirus and Avast too confusing. It has a simple interface, completely automated features, access to cloud-based protection, and has been shown to be very good at protecting a computer. Panda Cloud Antivirus has a behavioral blocker, web protection, and access to cloud-based protection, all of which will help increase your security.


AVG Anti-Virus Free EditionAVG Anti-Virus Free Edition is also a decent choice for average users. My analysis of the results, as discussed in the methodology section, does show that it does a decent job of protecting your computer. However, it appears that the above Antivirus products tend to do better. Also, it comes with advertisements (but they can be disabled).


Avira AntiVir Personal EditionAvira AntiVir Personal Edition is another product which has a very good reputation. However, the free version was not tested by any of the three testing organizations I referenced in my methodology. Therefore, I cannot currently recommend it above any of the previously mentioned products.

However, other comparative tests do show that it has very high detection rates for malware. Also, many users have used it and found that it is very effective. Also, users have access to cloud-based protection. AntiVir is certainly a good choice for a free antivirus, but due to the lack of real-world testing, at this time I cannot recommend it above the other products in this review. Hopefully in the future they will have the free version tested by these organizations as well.


Bitdefender Antivirus Free Edition

Bitdefender Antivirus Free Edition is another free antivirus product which has a very good reputation. However, the free version was not tested by any of the three testing organizations I referenced in my methodology. Therefore, I cannot recommend it above any of the previously mentioned products.

The engine for this product appears to be the same as for the commercial product. However, the level of protection provided has not been shown identical with the paid version, which is why I did not use the results for the paid version in my analysis. The user interface for this product is very minimalist. Thus, it may be attractive for novice users, though more advanced users may be frustrated at the lack of customization. Bitdefender Antivirus Free Edition is a good choice for a free antivirus, but due to the lack of real-world testing, at this time I cannot recommend it above the other products in this review. Hopefully in the future they will have the free version tested by these organizations as well.


Please help us by rating this review

Related Products and Links
Related Free Antivirus Software Articles

Related Security Articles

Have Your Say

Please visit our freeware forum to share and discuss your views and get advice on free security software, including antivirus software. To post in the forum you need to register first but that's quick and immediate.

Quick Selection Guide

Comodo Antivirus
Gizmo's Freeware award as the best product in its class!

Runs as a stand-alone program on a user's computer
This has full real-time protection capability, including real-time antivirus, behavioral blocking features, cloud-based protection, and an automatic sandboxing function which protects users from nearly all malware.
The automatic sandboxing function, although not very intrusive, may be too talkative for some users. Also, by default non-intrusive advertising is enabled (although it can easily be turned off).
Version 6.x
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.
Windows XP, Windows Vista, Windows 7, Windows 8.x

Take care to avoid the installation of unwanted software during installation. To do this use the customized installer button, which is on the lower left-corner of the screen during installation. Additional software, including a browser, an ad-blocking addon, and an option paid service which would allow Comodo technicians to help you with computer problems, are all included by default.

Avast! Free Antivirus
Runs as a stand-alone program on a user's computer
This has full real-time capabilities, behavioral blocking features, script malware protection, and a low rate of false positives.
Default settings require certain user interaction. It is bundled with Chrome browser by default, and if not carefully avoided during installation the user may accidentally install OpenCandy (see discussion for clarification).
Version 9.x
32 bit but 64 bit compatible
Feature limited freeware
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x, Mac OS

Take care to avoid the default inclusion of the Chrome browser and OpenCandy during the install process by using the custom install option. The attempt to install these will also be repeated at the program update if the automatic option is chosen.
Quick Start Guide:

Panda Cloud Antivirus
Combines a web service with a stand-alone program
High detection rate of malware, web protection, some behavioural blocker features
Detection rates of real-world malware is slightly lower
Version 2.x
32 and 64 bit versions available
Free for private use only
There is no portable version of this product available.
Windows XP, Windows Vista, Windows 7, Windows 8.x
AVG Anti-Virus Free
Runs as a stand-alone program on a user's computer
Behavioural blocker
Slightly lower signature detection rates
Version 2013.x
32 and 64 bit versions available
Free for private use only
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x

Forum for support

Avira AntiVir Personal Edition
Runs as a stand-alone program on a user's computer
Outstanding detection of malware
Not the most user friendly
Version 14.x
32 bit but 64 bit compatible
Free for private use only
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x
Bitdefender Antivirus Free Edition
Runs as a stand-alone program on a user's computer
High detection rates, very user friendly
Lack of customization
Version 1.x
32 bit but 64 bit compatible
Free for private or educational use only
There is no portable version of this product available.
Windows 2000, Windows XP, Windows Vista, Windows 7, Windows 8.x


This software category is maintained by volunteer editor Chiron. Registered members can contact the editor with any comments or questions they might have by clicking here.


free antivirus, best free antivirus, free antivirus programs, free antivirus program, antivirus software, free antivirus software,  antivirus program free, anti-virus programs, antivirus scanner, best antiviros, best antvirus

Back to the top of the article


Share this
Average: 4.3 (1965 votes)
Your rating: None


by Chiron on 23. March 2014 - 16:06  (115226)

Thanks for pointing this out. I would advise that users download and install V7 rather than V6. It is the newer version, and appears just as stable.

However, until the main Comodo Antivirus page updates such that it is V7 which is downloaded, I will keep the version listed as V6.x. This way it will not confuse users who are already running it, and try to see if there are any updates.


by Chiron on 22. March 2014 - 15:54  (115185)

No it is not. The final version has been released to the forum, although those running V6 will not yet receive an automatic update. Also, I'm not sure whether the main download page directs users to V7 or V6. Regardless, the release topic on the Comodo forums will allow users to download V7 final.


by famewolf on 22. March 2014 - 20:54  (115199)

Not directed at Chiron specifically but is a direct link to the v7 download or topic to much to ask for? Normal download process gives me V6 and I'd like to avoid having to hunt through their forum for it.

by Chiron on 22. March 2014 - 21:06  (115200)

I have updated the review to point towards, and reference, V6.3. However, if you would like to install V7 you can find it here:


by rseiler on 23. March 2014 - 6:07  (115216)

Do you know why it's 220MB? I know software keeps getting bigger and bigger, but is there something in particular about this one that makes it perhaps the largest?

by Chiron on 23. March 2014 - 16:08  (115227)

Unless I'm mistaken, the main installer contains the files for both the x86 and the x64 versions. During installation it will automatically install the correct files. It also contains the additional software, which I warn about in my review. I believe some 3rd party sources may remove those extra software. I hope this is helpful.


by George.J on 23. March 2014 - 6:41  (115217)

Comodo Antivirus is just 100MB download:

The Internet Security version has firewall and such, which most basic antiviruses doesn't have.

by famewolf on 23. March 2014 - 6:44  (115218)

If you follow Chiron's v7 download link you'll see the new version is 220mb.

by George.J on 23. March 2014 - 6:47  (115219)

Not sure what's happening there...

Although they have given three different links, all link to the same setup file [220MB download]. I mean why should IS, Antivirus and Firewall have the same setup size.

Softpedia link points to Comodo Antivirus 7.0 and is a 100MB download [x64 version].

Probably the link given in the forum is just one setup file.

Edit: The x86 version is 220MB download while x64 version is 100MB. [puzzled].

by famewolf on 23. March 2014 - 6:49  (115220)

Although all listed their size as 220m I did notice all three had different md5sum's...can you post the direct softpedia link?

by George.J on 23. March 2014 - 7:00  (115222)

Also note: Comodo Internet Security at this Softpedia page:

Shows an x86 and x64 version [both <100MB file] and a Universal Installer version [220MB], giving you free choice to install the version you like.

by George.J on 23. March 2014 - 6:50  (115221)

x86 version is a 220MB download while x64 version is 100MB.

[Link removed - direct download links are not permitted. Please use the site PM system for this]

by sicknero on 22. March 2014 - 16:17  (115186)

Thanks Chiron, I'm running v6 CIS and as you say it isn't reporting any available updates.

I had a look around Comodo and FileHippo etc (the screenshots on FileHippo look like v5?) and the Comodo download appears to be v6 still, so I thought I'd ask here.


by Chiron on 22. March 2014 - 16:20  (115187)

I thought about this some more, and what I have ended up doing is I edited the information so it now reads V6.x. This way there will be no confusion. Once V7 is made available through the auto-updater I will update this to refer to V7.x.

Thanks for pointing this out. Let me know if you see any other issues with this review.

Thank you.

by Roderunner on 22. March 2014 - 12:43  (115182)

The 'Sandboxing' feature in Avast has been removed.

by Chiron on 23. March 2014 - 0:40  (115203)

I was not aware of this. However, it looks like this was removed and the DeepScreen feature was added. I will update this review accordingly.

Thank you very much for bringing this to my attention.

by bernardz on 22. March 2014 - 0:27  (115173)

Although it is not as good an antivirus system as these above, MSE does have the advantage that it can run on slow machines without draining the power too much. It also has no legal issues about commercial or non commercial use. For these reasons for many people, it is actually a better solution.

by George.J on 22. March 2014 - 4:20  (115175)

Check here, and you'll see that Avast is the lightest antivirus using least memory resources. The way it flushes/resets the memory after every 10sec is an innovative feature to keep memory usage under check.

I admit that the results doesn't take into account the processor usage.

by Chiron on 22. March 2014 - 1:56  (115174)

If you check the results for MSE, you will find that it consistently scores near the bottom. Thus, it does not offer sufficient protection for me to recommend it in this review.

For users who find the other antivirus products in this review too resource intensive, I would recommend that they try Panda Free. It should be quite fast, even on slow machines. As per legal issues, Comodo Antivirus is free for commercial use, although if the company has many computers they may wish to consider Comodo Endpoint Security, which is paid. That said, there is still a free product recommended in this review which also works for commercial environments.

Everything taken into account, I do not think that it is a good idea to recommend MSE. It just doesn't provide the level of protection which people deserve.


by Chiron on 21. March 2014 - 23:31  (115172)

Hello, I've just completed a major revision of this article. Therefore, if anything seems wrong, such as a link is not working or the wording is unclear, please let me know. This is still a work in progress, but I wanted to provide you with my new ideas, and testing criteria, now rather than later.

Please let me know what you think of the new review. Your feedback is much appreciated, and will be very helpful.

Thank you.

by davy on 21. March 2014 - 11:46  (115168)
by Chiron on 21. March 2014 - 12:38  (115170)

Yes. If users have trouble uninstalling Avast, or experience other problems after uninstalling it and then reinstalling it, this uninstall utility is very helpful.

by sonoffar on 20. March 2014 - 22:02  (115156)

In hopes of hardening my older XP Pro lap top before the SHTF event in April, I loaded up Avast and was initially satisfied with how it did it's job. Then I reached a 30 day anniversary and the constant nags started. Now I have no working anti-virus and I am also unable to remove Avast or disable it's constant nag pop ups. As of this date I would rather be scalded than pay the Avast pirates a penny for their miserable product.
Anyone looking for free anti-virus I would advise stay well clear of this nasty, intrusive, offering.

by Chiron on 20. March 2014 - 22:28  (115158)

As sicknero mentioned, did you register the product? Regardless, it should still be able to be removed (and if it can't this sounds like a bug), but the reason it's nagging could very well be because of the required registration.


by sicknero on 20. March 2014 - 22:13  (115157)

The free version of Avast requires that you register with them to use it for more than 30 days.

I'm guessing that you didn't do that?

by althu21 on 8. March 2014 - 7:44  (114886)

What about Qihu 360 Internet Security?

by MidnightCowboy on 8. March 2014 - 9:14  (114889)

Only products with a proven history over a long period outside of their domestic environment are likely to be considered for this review. MC - Site Manager.

by dbnnet on 7. March 2014 - 14:13  (114868)

Have been testing AVG, Avast! & Avira. So my 2 cents, for what its worth:

1. Whilst AVG certainly is very capable and suitable for the vast majority of users, it does tend to be a bit "heavy" and slow, but all round a solid product.

2. Avast! may well be rated highly, BUT be warned.... its a bandwidth hog, doing all sorts of strange things in the background. At first I thought it was a bug or something weird going on... but a quick search on Google shows that this is well known. If you are using 3G or any form of controlled bandwidth, suggest you leave Avast! well alone! Setting to a minimum file only protection did not seem to help the situation either.

3. Avira.... have since 2013 removed their intrusive ads (This needs to be updated in the above summary). I currently use this Anti-Virus, and have no issues so far!

by Chiron on 20. March 2014 - 22:49  (115161)

I have removed the warning about Avira from the article. Apparently they now provide free users access to their cloud as well. I have updated the article to mention this as well.

As for the other products, I will be updating this article (once I have more time) to better differentiate between the real-world protection offered by the various products. To do this I will draw on the results from several testing agencies. However, I am very busy right now and not sure when I'll find enough time for a drastic rewrite and research which this necessitates. That said, it will happen eventually.

I was not aware of the issues which Avast causes on systems with slow internet. I assume that is likely caused by cloud-based activities. Has anyone else run into a lot of problems with Avast hogging the band-width? If so I'll update the article to warn about that.

Thank you.

by AJNorth on 4. March 2014 - 18:17  (114782)

Avira Free Antivirus has been updated to version (2014.03.04; 132 MB).

(Again, the update nag screen has been eliminated.)

Gizmo's Freeware is Recruiting!

Gizmos Needs YouShare your knowledge of free software with millions of Gizmo's readers by joining our editing team.  Details here.