Introduction
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

Platforms/Download: [field_blackberry_download] | Windows (Desktop) |
Version reviewed: 2019
George.J
Our Rating: 5/5 |
![]() |
- 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 more...
- 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

Avast Free Antivirus
The only antivirus with a fully customizable installer and selection of user preference components.
Platforms/Download: Mac OS | Windows (Desktop) |
Version reviewed: 11.1
Gizmos Freeware
Our Rating: 4.5/5 |
- 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 more...
- 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]

Comodo Internet Security Premium
Provides a multi-layered protection scheme with HIPS, sandbox, antivirus and firewall.
Platforms/Download: [field_blackberry_download] | Linux | Mac OS | Windows (Desktop) |
Version reviewed: 8.2
Gizmos Freeware
Our Rating: 4.5/5 |
- 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 more...
- 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]
Platforms/Download: [field_blackberry_download] | Mac OS | Windows (Desktop) |
Version reviewed: 8.2
George.J
Our Rating: 4/5 |
- 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 more...
- 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

Avira Free Antivirus
A free antivirus with high quality signatures, very fast updates and less false positives.
Platforms/Download: [field_blackberry_download] | iOS | Mac OS | Windows (Desktop) |
Version reviewed: 15.0
Gizmos Freeware
Our Rating: 4/5 |
- 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 more...
- 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

Panda Free Antivirus
Gives you antivirus protection with low memory and CPU usage, and collective intelligence cloud security.
Platforms/Download: Windows (Desktop) |
Version reviewed: 16.1.1
Gizmos Freeware
Our Rating: 4/5 |
- 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 more...
- 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
Honorable Mention
- AVG Free Antivirus
- Baidu Antivirus
- Bitdefender Antivirus Free
- Clearsight Antivirus
- Fortinet FortiClient (Most Improved products of 2018)
- Nano Antivirus
- Roboscan Internet Security Free
- Sophos Home Antivirus
- Tencent PC Manager (Most Improved products of 2018)
- Windows Defender on Windows 10 (Most Improved products of 2018)
- ZoneAlarm Free Antivirus + Firewall
Related Products and Links
How to make an antivirus engine
Other Articles By Chiron
- How To Avoid Spam
- How to Clean An Infected Computer
- How to Fix a Malware Infected Computer
- How to Harden Your Browser Against Malware and Privacy Concerns
- How to Install Comodo Firewall
- How to Know If Your Computer Is Infected
- How to Protect Your Online Privacy
- How to Report Dangerous Sites
- How to Report Malware or False Positives to Multiple Antivirus Vendors
- How to Report Spam
- How to Stay Safe While Online
- How to Tell if a File is Malicious
- How to Tell If A Website Is Dangerous
Related Free Antivirus Software Articles
- Best Free Adware/Spyware/Scumware Remover
- Best Free Trojan Scanner/Trojan Remover
- Best Free Rootkit Scanner/Remover
- Probably the Best Free Security List in the World
Related Security Articles
- Gizmo's Guide to Securing Your PC
- Safe Computing in Under an Hour
- Best Free Internet Safety Check Freeware
- Best Free Browser Protection Utility
- Best Free Firewall
- Matousec Personal Firewall Tests Analyzed
- Best Free Intrusion Prevention and Detection Utility for Home Use (HIPS)
- HIPS Explained
- How to Surf More Securely
- How to Improve Your Security When Using a Public Terminal
- Best Free Spam Filter for the Average User
- Best Free Spam Filter for the Experienced User
- How to Reduce Spam
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.
Editor
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.
Comments
I too intensely dislike the newer Avast. I used to work really well, but starting this year (even though they said they still supported Windows XP) every attempted update crashes and will not complete. Secondly, it is constantly trying to change my search page to Bing or Yahoo will and not allow my current Google. I have read complaints from others who state that once having allowed the changes they cannot be undone. Point 3, the newest update has severely slowed my ability to use the internet and even do anything locally on my machine (once I uninstalled Avast, everything returned to usual).
I will no longer use Avast! Especially since the recommend Yahoo and not Google. I no longer use Yahoo because of spam issues.
"Bitdefender Antivirus Free Edition" has a serious problem, I tested it on three different computers running Windows 7 x64, and on each one the program/installer was in Romanian and the option to change the language was greyed out, this issue has been there ever since it came out and I never managed to find a solution for it.
Also, I'd like to know your thoughts on "ZoneAlarm® Free Antivirus + Firewall 2015" I've used it in the past and my experience with it was quite positive.
I always download it from Bitdefender's official website: http://www.bitdefender.com/solutions/free.html
Thanks for pointing that out, I will check the other article.
One more thing, I'm curious as to why "MSE" isn't included in that list? From my experience it's an excellent set-and-forget antivirus and correct me if I'm wrong but I believe it has been integrated in Windows 8 and higher.
Not possible, all three computers I tested this issue on they are in English.
I also just tested right now on my own laptop (running Windows 8.1 x64) and I'm having the exact same issue.
Screenshot (before): http://i.imgur.com/JZInEn8.png
However I managed to find a workaround for this issue here:
http://forum.bitdefender.com/index.php?s=062f69887726794a3d52beac180a072...
Screenshot (after): http://i.imgur.com/aaOoAgd.png
I tried it today briefly but it was disappointing. During the initial scan it stated that it found and cleaned 16 infected files which is highly unlikley considering the semi-empty PC I was testing it on, but even when I opened its log, it was empty. Also, the fact it has no options to speak of leaves a lot to be desired.
Indeed, I wanted to try it several times but was unable to due to that problem.
In any case, I'm glad I could help.
Well, I tried it, I'm sure it's a wonderful program, BUT, even after a careful installation, it nags the devil out of you to sign up for the stuff you didn't want. Have been using Bitdefender for a year, no problems. Before that, was using Avast, my favorite, but Avast changed something in their detection rules and it would not allow me the see my security cameras for remote sites. I have income properties in other states.
So, ran a scan with the Comodo antivirus, O (zero) detection. This tells me that the Bitdefender is doing its job, and I am ALL OVER the internet.
Sorry, I can't for the life of me see why anyone would rate this as their number 1 source for protection. It's intrusive, and it nags the heck out of to sign up for the add ons you didn't want in the first place.
Excellent review as usual Chiron. I'd been using the free Avast AV/Comodo firewall combo for about 2 years but problems with Avast updating and your favourable Comodo AV review led me to ditch Avast and replace it with the full Comodo Internet Security free suite. Much less hassle having everything in one place and not having to worry about conflicts and creating exclusions etc. Things are now noticeably quicker.
One thing I didn't mention was what a nightmare it was to uninstall Comodo firewall to do a clean install of CIS Premium, even using your guide on the Comodo forums (Revo, both removal tools etc). Lost internet connection, CIS wouldn't install and restore wouldn't work due probably to either remnants of Avast or Comodo firewall. I finally got everything to work a considerable time later.
You're right about the firewall driver. Neither removal tool nor the uninstaller removed it. Your advice to remove it manually is several steps after rebooting into safe mode, so it hadn't been removed before doing this.
Regarding how I managed to get things to work, things are a little hazy due to a fair bit of red mist, but I went through the uninstall procedure again with Avast (2 removal tools like Comodo) and Comodo Firewall, still wasn't able to install CIS but at least restore then worked so as a last resort I restored to before trying to uninstall Comodo Firewall, and just went through the whole laborious process again and eventually it worked.
Good Day A ! Hi George.J ! I am a current user of 360 IS and am considering switching to 360 TS for support reasons as you know. I'm curious if you could tell me more about your experience with 360 TS compared to 360 IS regarding detection rate, resource usage, boot up time, scan time, and how well 360 TS plays with other software, such as MBM and SAS. Never mind George, I have already found answers to my questions.
Pages