Best Free Antivirus Software

  Read this article in Spanish
  Read this article in Chinese


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  • Excellent malicious URL blocking, network protection, outdated software checking, integrated password manager, and comes with a rescue disk.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

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...

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

How to make an antivirus engine

Other Articles By Chiron

Related Free Antivirus Software Articles

Related Security Articles


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.

Back to the top of the article.


Please rate this article: 

Your rating: None
Average: 4.3 (2219 votes)


Some may find the following post in the Avira Support Forum of interest:

"We’ve listened: Goodbye Notifier Ads!

Dears Customers,

The so called “Notifier” which for the Free Antivirus users pops up once a day (if you didn’t install the Avira Search Free Toolbar) to sell you something is about to disappear.

Starting with October 1st, you will never see it again.

For more information, please have a look here: ."

- - - - - - - - - - - - -

In addition, the first Beta of Avira Free A/V 2014 has been released.

That is excellent news!

I agree, JT.

Of course, it remains to be seen just how well v. 2014 will perform, so Neil Rubenking's testing & review (PC Magazine), along with those of the various A/V testing labs, are eagerly awaited. (Too bad they're apparently retaining the Ask toolbar...)

As a side note, given the recent positive reviews that Comodo Internet Security has garnered (AV-TEST; Tom's Guide), might you consider putting it in the queue for a review?



Interesting that this announcement follows their recent relatively poor performance in AV tests. They used to be regularly in the top few but seem to have slipped lately, perhaps this is a way to offset this.

I don't use it any more though and can't say the advertising ever bothered me that much anyway.

They should have done this a lot earlier, but I will take it. Any news on the webshield and the ask toolbar in the free version?

The only description of the 2014 Beta I am able to find at this time is at . Under "What’s new in Avira Free AntiVirus 2014 Beta," it describes a fix to the ask [sic] installer, so it appears that the toolbar has been retained, unfortunately (hopefully as a selectable option). They also provide a download link (the executable is 117 MB).

With Avast, you have to be careful not to get stuck with the Internet Security.

How does rank?

My new PC came with Windows 8 - are there any recommended free antivirus/antispyware programs I can use with it?

Any of the AVs suggested in the review will work fine. You can also read the comments to look for suggestions which are not covered in the review. I personally use Avast, and it's working great with Windows 8.

On their website ( ), it says Comodo Internet Security is free. I've no idea as I've never used it. It also scored well: .


Having used the Comodo Firewall (in various incarnations) for over a decade on several machines (with high regard), and their full suite off-and-on, my experience with the current version running on a client's Win 7 laptop (I7-3630 QM, 8 GB DDR 3) for the past four months has been quite favorable.

Comodo I.S. has enjoyed a reputation for keeping a clean system clean; its ability to remove detected malware had been somewhat low previously, but has been improving of late.

A recent overview by Tom's Guide of the various free antivirus solutions discussed above, and a few more, can be found at,review-178... . From their conclusions:

"If, in your eyes, protection against malware is more important than the defenses against phishing and Web threats, then Comodo wins with some top-notch real-time defenses."

As that well-known disclaimer goes, your mileage may vary. Best of luck.



IMO their conclusion is a bit ambiguous considering most malware now comes from web threats. MC - Site Manager.

Indeed; all the more reason to employ a defense-in-depth strategy, which includes (amongst other things) using a secure browser (such as Firefox with an add-on such as NoScript) -- not to mention not doing casual browsing with administrative privileges (or much of anything else, for that matter...).

Still, the results reported by AV-TEST are impressive.

Qihoo 360 Internet Security is really an excellent freeware suite worth and evaluation


Can you please till me if Avast is still the best choice as free antivirus software or not, i am asking because in your review i noticed that you rated "Microsoft Security Essentials" and "Avira AntiVir Personal Edition" with 5 stars and "Avast! Free Antivirus" with 4.5, so i want to know if "Microsoft Security Essentials" is the best choice now or not, or it is "Avira AntiVir Personal Edition" or it is still "Avast! Free Antivirus"?

I follow your review for my choice so i want to know which is the best now.

And thank you so much for your review.

Avast is certainly one of the best choices, basically any of the major AVs provide good protection with good computing habits. :) The rating shouldn't be displaying that, my bad.

Hi RandyDoqa, of you take a look at my prevoius post you will understand that the 2 best free AVs are #1BitDefender AV free edition and #2avast free antivirus. BD free has no settings and no advanced features but it's using the same engine and definitions as the paid products of Bitdefender(AV of the year and best repair of the year) so it has the same detection as the paid products of BD. My favourite AV is Avast, it has many features, but it doesn't have the detection rate of Bitdefender. So the choice is yours- Bitdefender or avast(i mean that are the best free AVs in the world). Of course you can use other AVs but these are the ones i recommend. Oh, and don't believe that Qihoo 360 is better than these AVs, it has no chance against them. :)

i found this here on your website,i have been using it for a month now and i would like to say that maybe its time we take one of the everyday we hear about antivirus programs that are bloated so badly today and help out those that brought me Unthreat Antivirus.Hope this isn't against the rules,but if anyone else out there is looking for a good antivirus,give this a try.thanks love the website.

There is another great AV, Bitdefender (it is the Antivirus of the year according to AV-Comparatives and has won the Best Repair for 2012 award from AV-test) and it has a free version, which you can download from here: Note that you can't configure any of it's settings, but it takes care of everything automatically and discreetly using Top notch technologies). And, my favourite is Avast. It has more features than any other free AV. In the tests, Avast is outperforming every other free anttivirus program, incl. Your #1 selection, Avira. The only free AV which beats Avast is Bitdefender. And like they say- "It beats all viruses...and antiviruses. Always AWAKE) So, the #1 AV should be Bitdefender, and the second, my favourite Avast. Thank you for the great site, Ian!

Edit: MSE has a very very low detection, in fact, it has the lowest test results, LOL

I used Avira for several years. But Avira finally started upgrading itself on its own to v13 after bugging me everyday to do the upgrade (and me refusing). Not cool. Then it tells me to uninstall Spybot and (I think it was) Emisoft as they are "incompatible". Also not cool.

So fine. I uninstall Avira and start installing Avast. But I'm reading its eula and I get to the disturbing part below. It seems Avast is now spyware and DOES collect your personal info and provides it to its "business partners". VERY uncool!

Is this new? Do others find this objectionable, too? Am I misinterpreting something? Other parts of the eula were questionable as well.

[below is copied from eula]

"Notwithstanding anything to the contrary in the AVAST privacy policy, you consent during the term of this Agreement and for one (1) year thereafter to (i) AVAST sharing information collected by you during your installation or registration of the Software with AVAST’s distributors and other business partners and (ii) use of such information by AVAST, its distributors and other business partners to present you with information that may be relevant to you, including offers of software, services or other products."

I ended on this site looking for review that might address the fact that, as you mentioned for AVAST, these guys are collecting data on us and passing it around to there friends and [of coarse] making money on it some how. I decided not to stay with AVG because of there personal data collection policies, "email, web sites" and more. That was enough for me. Soooooo...... what to do.

That would be a real help to the masses [like us] if techsupportalert could include in there reviews if the AV software collects personal data and if it does, what data and how much.

The majority of software vendors collect user data for either marketing or product improvement purposes. Exactly what they do collect is detailed in their FAQ and EULA which users should read before installing the software. Additional information that may be of concern to some users can be found in their own support forums, and in the case of security software, in the Wilders forum. Gizmo's Freeware will not be including this type of information in reviews unless there is a major concern about any one product which would likely be removed anyway. MC - Site Manager.
Exactly it's just that these users are too paranoid about privacy, when most of the information collected are non-personally identifiable. Also FAQ section of good software's covers what information they collect.
I wouldn't be surprised since most softwares have EULA along these same lines. (i) "Sharing information" as in the samples found in individual computers for testing false positives and other information. Using the same to update database signatures etc etc... I think can disable this by deselecting Avast Community Program. (ii) Mailing you about Avast information, according to your preferences, and finding if you have Chrome installed on your PC, if not recommend the product to you during installation. Definitely not spyware.

360 Internet Security 2013.
From more than last 7 years I'm a regular visitor of this site.But this is my first post as yesterday I saw a review on 360 internet security. Then I searched about the software & got interesting results.
Quick installation. Attractive interface. Good scores in antivirus tests, both from PCMag and independent labs. Built-in feedback form for reporting any problems.,2817,2422024,00.asp

Anyone who's looking to download the software can go to the official English website:

BitDefender has recently updated their free Anti-Virus and the new version includes real time protection (about time IMO). As I understand it, the software is based on last years commercial AV product rather than the current release, but I do remember seeing some very good reviews for it at the time. The software itself is light and fast, very simple to use with very few settings or advanced options to play around with, in fact once installed you hardly know it is there. If you're looking for an install and forget AV package this may be the one. Will be really interested to see how you guys rate it against AVAST and the others.

Oh BTW I had to download it from the USA site, the version available on the UK site is still the old software with no real time protection. Just switch the country at the top of the screen to USA and then download the software.

The antivirus portion seems to work fine; but the program is blocking me from known good sites like: instantbird, portableapps download section, some downloads on sourceforge; etc. ....and when clicking "continue anyway" it does not seem to react properly. just my take.