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...

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  • Excellent malicious URL blocking, network protection, outdated software checking, integrated password manager, and comes with a rescue disk.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...

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...

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

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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)


Thanks for the heads up!

Not happy with Avast! 8. On first install on Windows XPSP3 got BSOD. Re-installed and managed to get it running but cannot get it to appear context menu even though ticked in setting. Have been to Avast's forum and it appear manay other people with XP are having a similar experience. One says they paid for the full security suite because of the Sandbox feature, but that feature is not working, so they're certainly not happy.

I tried to install Avira but it came up with a message stating not compatible with Malwarebyte Anti-Malware which I have install.

Until Avast sorts out the problem with version 8 I'm ditching it and will give MSE or AVG a try.

Anyone else experiencing similar problems with Avast! 8 on XP?

The warning message that one often receives early during the installation of Avira Free A/V is for POSSIBLE incompatibilities. My understanding is that Avira are concerned with the possibility of more than one real-time scanner being installed; if one is not already present, then it should be perfectly okay to continue with the installation.

For the dozen machines I have Avira running on (XP through Win 7) that had various other security applications already installed (including scan-on-demand versions of Malwarebytes Anti-Malware and SUPERAntiSpyware, WinPatrol, SpywareBlaster and the Comodo Firewall), none experienced any issues interfering with the successful installation or operation of Avira (much less required any of the other apps to be removed).

Avast has a lot of realtime protection modules or features that while offering protection hook deep into the windows to do so creating the potential of things going south such as BSODs. When everything works, I believe Avast is the best free antivirus, but I wouldn't use it if BSOD my system.

My advice would be to uinstall it, and any remnants it has with the Avast uninstall utility, then reinstall it to see if that solved the problem.

If it doesn't, and you want a hassle free antivirus, I would personally recommend Panda Cloud, AVG, Avira and finally MSE in that order. I personally use Avast on my main desktop, and Panda Cloud on my low powered netbook.

Generally when new versions are released, specially major ones, they may take a bit of time to stabilize. Even with all the beta testing, possibilities of bugs are there, because of the many different systems with many different configurations. What I do nowadays, is to just watch their forum for a few days, after the release. If there are no major issues being reported, then I go ahead with the install. If there are major issues, the Avast team is prompt, and they release an update to address those issues, as they are posted and reported on the forum. So, if you encounter an issue, the best thing would be to post on their forum, and let them know about it, and give them details, so that it will help them in fixing the problem. Or, they will provide some help on diagnosing the issue, and fixing it, or directing you to an already posted solution on the forum for the problem. Avast had released a new version of Avast 8, fixing the bugs reported, so maybe you can try that? I haven't updated to Avast 8 on my machine yet, but will do soon. Have been keeping a watch on their forum.
The issues you describe are not uncommon, no matter what the product. Considering the huge number of successful Avast! installations however, such problems can often be related to local issues such as remnants left behind by other security programs, existing Windows system errors, prior use of so called registry cleaners or tweaking tools etc. However, if you are able to find an alternative that will install "as is", then this is likely preferable than trying to troubleshoot why Avast! won't. MC - Site Manager.

How does Bitdefender free edition hold up to Avast/Avira?
It leads the security suites always? Why isn't tested yet?

Lack of user control and too much automation with the cleaning process makes this far less desirable than other products. I have yet to see any antivirus that was false positive free, so one that offers no choice to opt out of file deletion is IMO a dangerous one. MC - Site Manager.'s review of the new Avast! Free Antivirus version 8 came out today. The Editor Rating is three-and-a-half stars (by comparison, the previous Free Antivirus version 7 got four stars).

I'm a long-time Avast! user (since the old version 4.x days), and I think the new version 8 with its new features and better detection capabilities is their best yet.

I know I've posted some PCMag test links myself in the past but I repeat they were for "interest" only and folks should not rely on these (or any other media tests) when choosing an antivirus program. It's also worth pointing out (again) that IMO products should not be downgraded for failing to install into a massively infected machine. 99% of users will already have their installation so IMO this is the basis on which the tests should be conducted. Take note of this from their commentary too: "Avast! is the first product I've tested using my latest collection of malware samples, so I can't make an absolutely direct comparison with other recent products. It detected 75 percent of the samples and scored 5.8 points for removal. The score would have been higher, but in a number of cases avast! left executable traces behind, some of them actually running. Malwarebytes Anti-Malware 1.70, Norton AntiVirus (2013), and Kaspersky Anti-Virus (2013) all detected 89 percent of my previous malware collection. The top score for malware removal, 7.1 points, went to Malwarebytes." In other words a totally meaningless comparison to quote Avast! against products from the previous sample group. Note also that in those results Malwarebytes came top. Every infected machine should also run a secondary scanner after that of the resident antivirus has completed. Our top recommendation is Malwarebytes. IMO an Avast! + Malwarebytes combination is going to perform more than adequately and in real use certainly a lot better than PCMag would have users believe.

Aloha all - I've been using AVast Free edition and generally I'm pleased with the product. I noticed however that with the update to latest version, the installer indicated that some personal information is collected by the Program and supposedly used only in aggregate form. Has this always been the case with this program, and also is that generally true of free antivirus products ?

All AV's collect some form of data, a safe rule of thumb is if all the voluntary data collection options are disabled you will be more than fine. Having said that even if they are not disabled it's not that big a deal.

Thanks. I'm sure most people would be more at ease if we knew exactly what info was being collected, but by the same token, in the absence of an available product that doesn't collect data, I suppose this is the lesser of two evils :)

Microsoft Security Essentials (MSE) has been updated to v4.2.223.1 (2013.02.27).

Thanks for the heads up!

You're welcome!

Avast just updated to version 8. There a lot of new features, but the core security modules look unchanged. Cnet also stated that "Changes to existing Avast features include increasing the number of virus definition file updates per day, from 20 or so in the previous version to more than 70 per day in version 8."

Don't know how that works, because they were already steaming updates that they pushed out that updated definition frequently, but it put in perspective that AVG free and MSE which by default on check for updates every 24 hours.

I assume Panda cloud is constantly getting updates via the cloud whatever that means, and you can schedule Avira to update itself to whatever frequency to want through the built in task scheduler GUI.

AVG free GUI options prohibits anything other than at least once every 24 hours(you need the paid version to change it), and MSE has various methods and hacks to make it update itself more frequently but they are round about and not for average users.

So if definition update frequency is any indicator of security, (may help for example zero day vulnerabilities) then Avast free, Panda cloud, and Avira are the go to choice.

I would take update frequencies with a grain of salt, there are way too many unknown variables for this to be an accurate depiction of results. There's the level of heuristics and how big the updates are for instance. I've said this before but really what makes a safe computer is a smart user, all good AV's (free or paid) offer similar levels of protection.

I believe it takes some importance. It isn't a coincidence that the paid versions of Avira and AVG check updates quite frequently. A practical and recent example is whenever there is a bulletin of a Java, Adobe reader or flash exploit in the wild. Most AVs will add definitions to defeat such exploits within 24 hours. Can't depend on heuristics in those situations b/c has been documented more than once where the collective AV scene fails to detect such exploits via heuristics. So it is urgent to get the definition to the users.

In this case, Avast would use it steaming update mechanism to update all its users ASAP to combat the exploit. However it problematic for AVG and MSE users depending on where they are in the 24 hour interval. If they are on the 23 hours, then they will get the update in an hour. If they are only on the 1st hours, then they will get it in 23 hours. Regardless, the user is vulnerable to that exploit just b/c of that arbitrary 24 limit, which was probably set in the first place to save bandwidth on its free edition users.

I also humbly disagree with the statement that all AVs are equal. MSE is a really basic definition based AV with a basic level of heuristics. In contrast, Avast goes step further by for example scanning browser scripts in real time that allows for blocking things like malicious iframes embedded in hacked legitimate websites, which is a big deal considering the average user is several time more likely to to get infected by hacked legitimate sites, then by purposely going into the gray intraweb.

Or course the users will always remain the most important factor in cyber security, I am sure the maintainers of this site and the like minded readers this article attracts, probably on average have better a lot better security practices than the average pc users, meticulously updating their software, and switching to non admin accounts and other things that would in the grand scheme of things is a greater factor in preventing malware than any singular AV. However, it doesn't hurt to have better AV when given the choice.

I agree with pretty much everything you said, however my personal bias (for better or worse) is that the extra protection offered by web/script scanners are minimal in the real world, as well as the point about practices as you mentioned. However I take your point that I may have under-appreciated the differences a tad.

In addition to its configurability, Avira Free A-V 2013 updates four times per day by default (previous versions updated once per day).

[Along with the software, the User Manual for Avira Free A-V 2013 may be downloaded at]

Hi Wolfram
I did as you suggest but hit a problem that when I try to manually update from the fsbdev file Avira says that it cannot update as the license is no longer valid.
Do you have any suggestions as to how to get a valid license for this version as it is no longer supported?