Best Free Antivirus Software

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To begin with let me say this: there is no best antivirus out there. Why do I say this? Any product that you take will behave differently against various virus samples since the AV engines and other components incorporated in them are of different technologies.

While one product might have higher detection ratio, another might have better malicious URL blocking or virtualization techniques, yet another might have lesser impact on system performance and so on.

Read more about Antivirus Engine and other related details at the end of this article.


Rated Products

Kaspersky Free Antivirus/ Kaspersky Security Cloud  

The paid security giant forays into free category and outsmarts its rivals

Our Rating: 
License: Free (Limited features)
  • Similar signatures & cloud features as its paid counterparts
  • Performance impact is decent on higher end systems
  • Strong behavioral blocker
  • Attractive GUI with no ads
  • Top-notch detection and always up-to-date
  • Thorough malware removal and disinfection process
  • Privacy policy (complies with GDPR)
  • Default settings cover most users
  • Bundles with Kaspersky VPN (can be uninstalled)
  • Fairly good web protection
  • Powerful exclusion settings (even for specific modules)
  • Extensive scan logs
  • Protection settings are locked with presets in Kaspersky Free Antivirus (KFA) [is available in Kaspersky Security Cloud]
  • Long but thorough system scans
  • Performance hit becomes worse on lower end systems
  • Slow update installation
Read full review...

Comodo Internet Security Premium  

Provides a multi-layered protection scheme with HIPS, sandbox, antivirus and firewall.

Our Rating: 
License: Free (Limited features)
  • Feature-rich with lots of options for customization along with setting tolerance against prompts
  • Tweaked settings gives the best 0-day protection among the pack
  • Multi-layered protection scheme with HIPS, Sandbox, Antivirus and Firewall
  • Industry grade firewall with options for learning and behavioural blocker
  • Low on resources with various graphical skins available and a clean user interface
  • Painful for beginners to use it, not very newbie friendly 
  • Av-module is a bit weak especially the signature based detection
  • Auto-sandboxing happens for various legitimate files, troubles with FPS games
  • Too many tweaks needed for better protection
  • Buggy software and updates are released slow.
  • Chromodo browser, Yahoo search engine, custom DNS and Geek Buddy offered during default install. [Click customize installation during install]
Read full review...

Avast Free Antivirus  

The only antivirus with a fully customizable installer and selection of user preference components.

Our Rating: 
License: Free (Limited features)
  • Extremely light on the system with a modern and clean UI
  • The only antivirus with a fully customizable installer, selection of user preference components
  • Works best in hardened or lock-down mode, which blocks all unknown programs (medium-expert users only)
  • Top notch detection capability, many secondary components to offer variety to a wholesome software
  • Excellent malicious URL blocking, network protection, outdated software checking, integrated password manager, and comes with a rescue disk.
  • Deep screen technology that includes Sandbox and Safe machine components for protection
  • Bloated default setup, some ads and pop'ups
  • Account creation for further protection after a month
  • Lack of an anti-ransomware module, and Deepscreen disabled by default
  • Cloud reputation, Malware signatures and HIPS module needs improvement
  • Offers Google Chrome and various bloated secondary components during install [Choose custom install]
Read full review...

Avira Free Antivirus  

A free antivirus with high quality signatures, very fast updates and less false positives.

Our Rating: 
License: Free (Private/Educational use)
  • Pretty light on the system and runs smooth without system slow-downs
  • Clean ad-free GUI, Ad-free installer, No pop-ups or ads
  • High quality signatures, very fast updates, excellent detection on non-zero day threats
  • Deep file scans with very less false positives
  • Avira Protection Cloud makes for an excellent cloud engine
  • Browser safety Add-ons available for major browsers
  • Zero day protection (heuristic & behavioural shield) is very weak. 
  • Ineffective Browser launcher which is a memory hog (can be uninstalled)
  • Painful removal for detected files. Repeated scans from Luke Filewalker increases CPU & RAM usage. 
  • Multiple file exceptions needs to be added (real-time and on-demand)
  • No firewall/sandboxing/web shield technologies
Read full review...

Panda Free Antivirus  

Gives you antivirus protection with low memory and CPU usage, and collective intelligence cloud security.

Our Rating: 
License: Free (Private/Educational use)
  • Low memory & CPU usage thanks to cloud protection
  • Tiled UI with customizable interface and nicely rendered Settings interface
  • Collective intelligence cloud security - Downloading virus definitions is history
  • Good detection rates and behavioural analysis program
  • Fairly good web protection and hardware resource handling
  • Dependant on internet connection leading to weaker offline protection
  • Slow scanning speed, no fingerprinting (successive re-testing same files) and at times issues with virus removal
  • Not really light, performance impact in web browsing, installation and copying
  • Certain false positives despite the information available at cloud
  • Watch out for Panda security toolbar during install
Read full review...

Qihoo 360 Total Security  

This free antivirus is better than most commercial ones.

Our Rating: 
License: Free
  • Totally free, light on resources, extremely fast scan times and pre-configuration protection modes
  • Smooth running installer with no adware, pleasing UI and comes with many themes
  • Fast updates/fixes and excellent customer service with immediate replies
  • Great signatures with multiple engines and in-house cloud protection
  • Web protection addon, browsing locking, webcam, sandbox and usb protection modules
  • Online shopping protection, malicious URL protection and network threat blocking
  • Includes Glasswire Firewall and Windows patch-up components
  • Great detection rates, with very high zero day protection
  • Speedup and clean-up tools might not be for everyone (not present in Essentials version)
  • Bitdefender or Avira engines not enabled by default
  • Might encounter few false positives
  • PUP [Potentially Unwanted Programs] detection needs to improve
Read full review...

Honorable Mention


Related Products and Links

How to make an antivirus engine

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Antivirus Engine

It is used for Real Time malware protection of files and is the core component to scan data on your PC for detecting and removing malware from hard disk, memory, boot sectors, network drives, removable disks, or from external network traffic (internet).

  • How does an antivirus detect malware:

Firstly you got the signature-based detection which contains an offline database of known patterns of malware downloaded from the internet which can identify specific malware codes or family of malware. Then you have heuristic based detection that identifies pieces of code that are unlikely to be found in legitimate programs and hence is prone to false positives depending on the sensitivity of heuristics. Virtualization and sandboxing unpacks or executes unknown programs in an isolated secure environment so that their behaviour can be analysed and scanned using the antivirus engine. The latest one is cloud based detection that requires a reliable internet connection and sends the suspicious scanned file over the internet and the analysis is done by the vendors' machine running the cloud engine.

  • Scanning for viruses:

Most antiviruses include these basic scan types: On-demand scan/manual scan is initiated by the user from right click context menu or from within the software. On-access scan is initiated when the resource is being accessed like running an executable, copying files from external drives etc. Scheduled scan periodically ensures that the system is free from malware by setting the time and frequency for scanning. Startup scan/quick scan checks most important locations like running processes, startup items, system memory and services, boot sectors and so on.

To be Continued in the next update....... Firewall, Proactive protection, Web protection components and more.



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

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Average: 4.3 (2219 votes)


Can you add a warning about Avast.
It tries very hard to install Chrome browser on install. You only get the option NOT to on Custom install
It also sneaks an attempt after restart after program update (this one has caught me several times)

This is a good point, thanks for bringing it up. As I always install software with custom settings I did not realise the severity of this.
Many freeware programs have their installers like this, where they try to sneak in the adware, and this is where Sandboxie and Winpatrol comes useful.

That is NOT what I expect from an AntiVirus product though.

Sandbox av??

I think George.J makes a valid point irrespective of the software type and especially where something as expensive to maintain as an antivirus product is concerned. These costs have to be funded somehow and vendors will use whatever means to do so whether end users find these sneaky or not. Also, the rise of this program type from countries such as Vietnam where costs are considerably less is putting further pressure on American and European producers in a highly competitive market. We try on a product by product basis to advise about wrapped installers and bundled toolbars but these are almost impossible to keep up with as vendors tend to swap and mix components regularly. In the end though the addition of WinPatrol will help users to avoid most of it as will a simple Google search of the product name beforehand followed by "toolbar bundled components". This will forewarn users about what they are likely to encounter and enable them to take the necessary steps to avoid it. MC - Site Manager.

I don't mind the attempt at inclusion on install, that one expects.

But having declined, I do think it is extremely immoral to allow automatic updates and to say restart to finish install and then sneak it in again on the notification of completion screen after the restart.
If you just click to clear this message ! BANG ! you get Chrome installed and set as default.

Yes, that is sneaky, and users have raised this issue over there in Avast forum too. That's why I avoid updating from within the program. I download the setup and then update it. Would also like to point out that home page change, startup entries, toolbars, etc. can be avoided by WinPatrol, but not these installations like Chrome with Avast. Also, you cannot install an antivirus in Sandboxie. General users avoid Sandboxie anyways.

Anyone considering AVG as their antivirus program of choice should read this article from earlier this year regarding malware-like behavior from an AVG product. The associated comments provide a number of solutions to the problem.

I also believe AVG has slipped down the ranks in the ratings of the testing authorities such as av-test and av-comparatives.

Of course it's asking for trouble to install 2 or more AV apps. But it can be done safely if one can be set to run in real time, the other to run only on-demand, as a cross-check of the realtime app.

I currently have Avast Free as my real time AV (quite happily) and Avira AntiVir on-demand because it has very strong detection rates with few false positives. But Avira's nag pop-ups are unstoppable, even after following many "proven" methods for getting rid of them that one can find on safe 3rd-party sites.

Now my questions. If I update Avira from AntiVir to the 2013 Personal edition:
a) can I still set it to run non-resident/on-demand only?
b) will the pop-ups stop?

a) Yes. You can disable the Real-Time Protection option in the main window.
b) Only the update/virus found pop ups. You can disable most of them in Options(Extras/Config/General).

I'm using Avira Internet Security 2013, by the way.

Re: Avast (not sure the correct section to post this)

Affects ADSL connection, tested a few times (uninstalled/installed)

Prior to install -

After Install -

No such issue with MSE

Update! After many attempts, searched solutions etc, for some reason I'm now not able to reinstall MSE, Grrr
Error Code: 0x80070643

I wish to praise all of the writers on this site. You have a very tough job. because there are people that don't agree with you. Then you have to put up with the criticism of those that don't agree with you. Like me........LOL You all do an awesome job.
Now for my criticism...LOL MSE has really fallen in there detection rates, I have run MSE on my system, and then ran all of the others behind it, to see what it missed. Every time I did that, it had missed something. Ease of use, does not make it a good anti-virus. I rank Avast as the best. That is a good call. It is just too much advertising for my taste though. From my testing, I would rank Avira number 2a, then AVG number 2b. I use AVG on my system. The reason I do is the ability to configure AVG to do what I want it to do. When I configure AVG to do a scan my way, it out performs all of the others. Panda is solid at number 3. MSE comes in at number 4. But MSE has become far to passive for me. At this point MSE does not even make it on my list.
If I could teach people how to configure AVG to scan my way, it would be number 1. God Bless you all for what you do!
Now for a request. It would be nice for this site to give a little lesson on how to use Task Scheduler within windows. I use it for so many things that do not have scheduled task within their programs. Examples : AVG does not auto update enough for my taste, so I use the task scheduler to do more updating. I also use it to run Ccleaner on a schedule. I think you would be doing the visitors of your site a great service, to teach them how to use the Task Scheduler within windows.

Thank you ALL so much for what you do!! I LOVE you all!!

It's a risky business looking at the various test results and then choosing an antivirus based solely on them. I'm in regular contact with many users of MSE, some in a businesses environment, and none are getting infected. The fact is that if your surfing and general PC usage habits are "infection prone", then you will be sooner or later no matter which security products are installed. It is also only of benefit to the community if you provide details about the "something" MSE supposedly missed, including the file path, and/or if like many Windows users, you have UAC disabled. :) MSE is designed to work as an integrated solution alongside other Windows security services so it will always give weaker results when tested as a single entity. In theory, MSE will always perform at a lesser level, especially where heuristic detections are concerned. There are however so many other ways to avoid zero day infections that blaming your AV for this is a poor option. Certainly for the more tech savy, a program such as AVG offers the possibility for greater overall protection. This can also lead to a false sense of security however for the reasons stated above. For average users though who have only basic PC skills, MSE remains a solid choice for it's simplicity when employed with safe surfing practices. Also, browser extension choice IMO plays as important a role as choice of AV and/or firewall. More information here: MC - Site Manager.

MidnightCowboy you are absolutely correct.

But if I were to give you all the technical aspects of how MSE fails on so many levels, it would take up this whole page and more. It is a mistake to disable UAC. Do NOT do that. I confess that I am not an average user. My rating system, that I gave, took the average user in mind. Otherwise, I would have put AVG as number 1. My parents are average users. They don't even know what a file path is. They have a false sense of security, because of their lack of knowledge about the Internet and the computer that they use. Every time I go to there house, I have to go through a whole cleaning process of there computer. They have one antivirus, I have six. AVG being the main one, then five scanners. AVG is NOT perfect, but none are perfect.
My point in responding , is to educate the average user without overwhelming them with to much of the technical aspects of using an antivirus program. But also to inform the more technical user of what might be a better choice.
I would advise anyone surfing the net to never feel secure. Just learn about the tools you are using to protect yourself.
MidnightCowboy, you are the best of the best. All my respect goes to you.

Thank you for responding. You are correct that our comments sections are reserved for just that and we always request more in depth discussions and other data to be posted in the forum. Many of our editors, including myself, do have direct contacts with vendors however and are more than happy to follow up information whenever possible. Please do post your scan results in the forum and we will then attempt to find out why MSE failed to detect them.

After my try with Avira, I am now considering whether I should change my AV. I like MSE for its non-intrusiveness, but the new versions rarely get released. Avira, on the other hands, has new versions more often, but it may have some annoying popups that I may not like too much.
I'm on a core I5 with 8GB RAM, Windows 7 Ultimate X64, and MSE didn't seem to eat too much resources, but I've heard from some of the comments that Avira doesn't use up as much resources as MSE.

Avira generally is lighter on resources than MSE, but I don't think it's a major concern with your computer. Using frequency of versions as a basis for judging AV's is probably not the most reliable. :) If you find the pop ups too intrusive, Avast or MSE are both good choices.

Neil Rubenking has published an article in PC Magazine that some may find worthwhile, "The Best Free Antivirus for 2013" (2013.05.08) --,2817,2388652,00.asp .

Thanks for the link, always appreciated!

I have decided to change AV software and leave MSE behind.

I've had on-going Windows Genuine Advantage issues when MSE tries to update - every morning this week when I cranked up, I got the warning that I have to reinstall the WGA plug-in for Firefox or MSE won't work.

Regardless of the issues, it's time to leave...

So, a question:

Is it better to go with a new stand-alone top rated AV, or maybe move to a Zone Alarm suite?

By way of a little background on my schema now:

MSE running in real-time

PrevX 3.0 running in real-time

On Demand: Malwarebytes, EmsiSoft Malaware, Hitman Pro 3.7

I have used PrevX since their introduction and like it, so I would like to keep it going and obviously need something compatible.

Thanks, in advance, for your thoughts and input...

Prevx is excellent and the only equivalents I know of are Panda Cloud AV and Immunet.

Given all the recent NSA and GCHQ revelations I would tend to avoid certain countries "free" products because they impact upon my own freedoms and I would install a European (non UK) tool such a Panda or other free AV. Before doing that, check out the company and where their R&D and partners are located though, certain countries are less trustworthy than others.

I firmly believe with a bit of common sense and safe practices you will be safe with a good free AV (any of the ones listed here). I think it's also important to note without those two things, the best paid security suite wouldn't fully protect you either. You have more than enough on-demand scanners as well. :)

There is some antivirus which slows down PC a bit as it uses more resource in your system while some don’t. Norton, MSE are such type of antivirus tools which will slow down your system. Immunet Free, Avira, Bitdefender etc. Are some antivirus which does not have much effect on computer speed and performance. Every antivirus tool automatically updates itself but you need to check automatic update box in software’s setting.

I personally use Immunet Free, here is a free download link to it -

Not sure why Avast is at the top, even though Webroot clearly is lighter from the tests and is regarded to be the lightest antivirus of all time, both in terms of installation size and while idle/scanning..

Webroot is very good, but it's not free.

I take back my words. I found that Avast flushes memory every 10 sec so the memory consumption will always be back to 5MB during scans (and never above 20MB), which I think is a great feature.

Avira have updated their Free Antivirus to v13.0.0.3640 (2013.05.07), 97.5 MB (off-line executable), a roll-up of product updates since the previous version's release -- (a 2 MB on-line installer is also available, as well as the User Manual).

Many find the pop-up nag screen that occurs with each update particularly annoying; a web search will provide the means by which to address this issue.

Thanks for the heads up!