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

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...

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  • Excellent malicious URL blocking, network protection, outdated software checking, integrated password manager, and comes with a rescue disk.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

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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Please rate this article: 

Your rating: None
Average: 4.3 (2163 votes)


Dont take all the tests too serious.Panda IS a great antimalware,and its okay light too.It would be my number one choice if I wanted a free antivirus.
Your ass is covered with Panda.

"Better" is mostly a subjective word. Like I already said in the Introduction part there is no Best Free Antivirus so I went through the Pro n Con structured layout in this article to make it easier for you to find an antivirus that best suits your needs.

The best thing you can do is to stick with your current antivirus, most preferably one among these mentioned in the article, while also reading through other alternatives if any particular feature in an antivirus attracts you. Otherwise you can try all of them, and stick with one. This is the best part of any software that's been offered for free.

I endorse 360 Total Security. I was introduced to it when a local print company using it picked up a threat on my USB that MSE had not detected.
now use both it and MSE and find they work seamlessly together.
I also like the Optimise Option on 360

I installed qihoo from the link and ran a scan. Now it has DESTROYED most of my programs. None of my browsers will work, I can not access Sustem Restore or Task Manager and no way to download replacements. I am in despair. (This is coming from an IPad>. M HELP

Got my system back. Thank God and Gizmo for the Ulimate Boot disk. Now following instructions at [link removed as it contains links to red-rated scam software] Although the registry keys seem to be gone already. Perhaps it did not install properly in the first place.

Further baffling, now Comodo is actually running for the first time since I installed it.
[Moderators comment: Please be aware the link you posted is to a scam site that appears to be legitimate but contains links to the red-rated SpyHunter rogue software. I even detailed this a short time ago in a post below. These folks set up dozens of domains linking to this rogue software and keep changing them as each site goes red with WOT (Web Of Trust). MC - Site Manager]

Your "download" button for Comodo is actually the link to Avira.
Also, there's a separate page for Linux antivirus.
I'm not so sure there's really any point because Linux is so virus-resistant anyhow. But it's good to see Tux getting some love.

Thanks, the link has now been corrected.

@ George J.
New to-be-considered contender in this category: SecureAPlus ( combining 12 anti-virus engines

SecureAPlus is considered to be a companion AV (an AV used for second opinion apart from your primary antivirus). It's mainly an application whitelisting (trusted) software that uses a block-first approach, where system is locked down after it's install and anything that's newly installed is considered untrusted/blocked unless you allow it or is available in their continuously updated list of trusted applications.

It also has AV scanning modules with it's engines available across the cloud that will block anything that has been detected as malicious. But from the FAQ ( it appears to be free only for a year, and then it can be extended only by adding referrals.

Dear editor, the "Go straight to the Quick Selection Guide" link on the page does not seem to work, please fix it.....

This has now been fixed. Thanks jawad.shafiq for the comment.

Many people would never consider Qihoo for fear of a Chinese government-mandated backdoor. True, this is speculation, but it does seem worth mentioning.

What made me nervous, was they do not appear to have a paid version.
When a company that has paid versions, also gives a simplified free version, I can sleep at night.


Qihoo 360 is multi-billion dollar company (unlike most other companies in this review), has more than 4200 employees and the revenue it might generate from selling it's antivirus product is quite meager. Just like Google, most of it's revenue comes from advertising (~68%), internet value added services (~30%) and only less than 1% from selling third party software. What started as a paid antivirus switched to the freeware model to gain market share and popularity in China.

I've used Qihoo in the last year but when i saw the same program was getting installed on other people's computers by malware and there are multiple sites telling you how to get rid of it because the uninstall doesn't remove everything I switched. True to form it did not want to uninstall and many parts had to be manually removed after the uninstall claimed to be successful. Multiple reboots later it still had processes running.

From the comments what I can understand is that certain people have been tricked into installing a rogue software that masked itself as 360 Total Security. There could also be programs that promote 360 TS and bundle their product with the antivirus software which may or may not be fake. Same is the case with many programs endorsing Google Chrome.

Now the end user is responsible in both these cases if 360 TS (fake/not) appears on their system in this fashion. The solution to this is to download programs from their official website unless specifically stated at Gizmo's Freeware with links to alternate sites.

Until last February I used to have 360 TS (before switching to Windows Defender) downloaded and updated on one of my systems through every iteration from version 5 and I have not experienced any problems like you've mentioned. To confirm that I downloaded 360 TS again day before yesterday, and had the same experience. It had the fastest install/uninstall times among it's counterparts, completely uninstalled itself without any "parts/modules" left behind, had no so called "processes" related to 360 TS running in the foreground/background after un-installation and reboot.

About the files left behind, after un-installing an antivirus you are supposed to reboot your system before the files are removed completely, which is why you might have seen folders of files related to it left behind. Even after reboot there might be certain empty folders left behind and some with files of few Kb's which does not affect system performance. This is true for any antivirus out there.

In the case of 360 TS the folders left behind after reboot were:-

  • 360 - C:\Program Files (x86)
  • 360 Quarant - C:\ProgramData
  • 360safe - C:\Windows\SysWOW64\config\systemprofile\AppData\Roaming\360safe 
  • 360Disabled - C:\Windows\Tasks

The same is the case with Avast::-

  • Avast Software - C:\ProgramData\AVAST Software
  • avast Antivirus! - C:\Program Files\Common Files\AV
  • Avast - C:\ProgramData\AVAST Software\Persistent Data
  • Avast Software - C:\Windows\System32\Tasks

This can be replicated for others too.

You had mentioned that 360TS had been installed by "malware" [from the very little information provided by you] which caused the after-effects so the original program is not the one at fault. The software from the official site doesn't include any adware/malware like you say, and this has been confirmed prior to writing this review. If you have any doubts about the same, and willing to trust Gizmo's Freeware for our reviews, you should try it yourself based on the recommendation before following up to what others have to say.

I installed qihoo from your link. It DESTROYED most of my programs, including Firefox and most of my start-ups. I could not uninstall it (went into Safe Mode to delete manually, but who knows what else is there)", and can not access Task Manager or System Restore. I can not install any replacements fort he destroyed programs,keep getting "no such interface" errors.
I am running System Restore from the Ultimate Boot CD and praying.

Over the years I've seen this issue caused by a variety of (mostly) security software especially in systems where several different security software apps have been previously installed. The fix involves the correction of registry errors. I suggest you Google for whichever you believe to be the most satisfactory solution but personally I do not recommend the use of automated registry tools, so the assistance of a qualified tech might be more appropriate. MC - Site Manager.

I too have had no issues whatsoever either with the running of this antivirus (when obtained from the official source), or its removal. This thread provides some insight into what might have happened to others. MC - Site Manager.

I definitely had obtained it from the official source. the uninstall appeared successful but left running processes behind. Your experience may vary.
My experience and the fact that it is installed by other malware for some people is enough for me to never go back.

Google Chrome and other popular software apps can also installed by the wrapped installers of other software so presumably you don't use any of these either? MC - Site Manager.

Wrapped installers are not the same as malware installing in the background. Google Chrome doesn't claim to be an antivirus program.

But you provide no details of what this "malware" is, where it might be obtained from, links to any of the "multiple sites" telling how to remove it, which processes were left running after the uninstall process on your system, in fact no concrete details about anything. MC - Site Manager.

You yourself posted a link of someone else who had it installed on their computer without their knowledge. A simple google search brings up multiple sites with similar stories and removal instructions. As for the processes left running, should I really be expected to remember the specific details from something multiple months ago?

amazing that I appear to be getting attacked just for relating my experience.

No one is being attacked here. If you search the various posts accurately you will see that this arrived as part of a bundled package so it did not get installed without user permission, rather, as is often the case, they just clicked yes, yes to everything during the installation of the other software and did not read the EULA beforehand. The fact some of the software bundles are from less than reputable sources is the reason why this became flagged as a PUP (potentially unwanted program) although both the software and the vendor are reputable enough. It is also worth mentioning that many of the "removal guides" for various software are themselves bogus such as these two (WOT (Web Of Trust) ratings links provided as the sites themselves are red rated). SpyHunter in particular is an infamous rogue and there are links to this all over the internet. As soon as one link goes red they set up a new domain. MC - Site Manager.

You may also find this of interest.

Certainly feels like being attacked. The post you linked to did not give any indication of being in a bundled package. I've seen other posts indicating similar. But gee thanks for the condescending link regarding bundled software.

Again, just relating my experience.

I've just uninstalled it with no problems at all. After the uninstall got a web page asking me why I had uninstalled and thanking me for trying it! Very polite :)

Hi, I have updated the article and we have a new top pick here. Any suggestions and feedback are most welcome. Good day readers!

Which one are you using George ?

Windows Defender mostly, but it's recommended only if you have sufficient computer knowledge and practice safe computing habits. On other's computers I install any one of the five.