Best Open Source Antivirus in 2023 [Out of 25 Tested]

Learn about open-source antivirus and what it can offer

by Radu Tyrsina
Radu Tyrsina
Radu Tyrsina
CEO & Founder
Radu Tyrsina has been a Windows fan ever since he got his first PC, a Pentium III (a monster at that time). For most of the kids of... read more
Affiliate Disclosure
  • Using open-source antivirus will benefit everyone who requires transparent security against threats. 
  • These antivirus software tools can be used for personal security needs or business requirements from organizations. 
  • If you have been looking for one, we have listed the best open-source antiviruses and their pros and cons.
best open source antivirus for Windows

Open-source antivirus software can help protect your PC against all digital threats, viruses, and malware. For those unaware, an open-source antivirus denotes a program for which the original source code is made available for free and may be modified and redistributed.

There are a few open-source antivirus software on the market that will bring you trustworthy security from all kinds of viruses or malware.

These security software tools provide advanced protection for different segments. So, let’s find out the best options.


Is there a good open-source antivirus?

There are not so many antivirus tools with open-source code that gives you the same piece of mind as a paid antivirus.

However, many big antivirus companies offer free versions of their main product with basic but highly valuable features. Keep reading to find the best one, and let us know if you know any other.

Another suggestion our readers made is about ClamAV. For those wondering if ClamAV is a good antivirus, based on our investigation, ClamAV is a reliable open-source antivirus with a plethora of features, such as detecting malware types, mobile viruses, phishing attempts, and digital threats.

Which is the best free version antivirus?

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As we said earlier, there are only a handful of reliable open-source antiviruses available. So, some options listed here might not be open-source, but they will be the perfect security software for your PC and protect against all kinds of threats.

Bitdefender – Best free antivirus overall

This award-winning free antivirus by Bitdefender is a real-time threat detection that runs smoothly in the background with minimum resources.

You can employ such reliable antivirus to resolve any cybersecurity issues like ransomware, spyware, or virus infection on your PC.

Plus, have a powerful detection rate for suspicious websites or executable files from your PC with complete scan engines.

This free antivirus is perfectly suited for high-resource processes on your system, such as video editing or gaming, because of its low impact on system resources.

In addition, benefit from security tools against internet fraud activities like phishing attacks or suspicious website behavior.

Let’s quickly look at its key features:

  • Web filtering technology
  • Advanced Threat Defense
  • Bitdefender Photon to save resources and improve the speed
  • Global Protective Network
  • Multi-layered ransomware protection
  • Vulnerability assessment
  • Autopilot for Security Advisor

Consider this industry-standard antivirus software to enhance your system health and performance without slowing down the computer.


Take full advantage of this completely free antivirus with the latest virus-free technologies.

Avira Free Antivirus – Best for virus or malware detection

antivirus router

Avira is another great security tool that will keep you safe from viruses, malware, and other types of cyberattacks, thanks to multilayered security.

The antivirus comes with a built-in VPN that will ensure your data stays private and nobody finds out your IP address, location, and identity.

More so, the program is free, without ads and other annoying popups. Simply install it and never worry about intrusive advertisements or offers.

Some of Avira’s core features include:

  • Advanced AI and machine learning
  • Cross-platform compatibility
  • Real-time protection and updates
  • Light on the system’s resources
  • Fast scanning

By choosing the complete antivirus tools from Avira, you will be relaxed about new emerging malware or virus threats.

Avira Free Antivirus

Secure multiple devices with this awarded free cybersecurity solution with a free VPN included.
Check price Visit website

Panda Security – Best for lightweight security

router antivirus

Panda Security is free cloud-based software that offers complete antivirus security for your Windows, Mac, and Android gadgets.

Firstly, you should learn about the highest virus detection rate and malware/spyware removal tools. You can schedule regular scans on your system and perform them conveniently.

With USB virus security, any user can prevent malware threats or hacking tactics with automatic execution from USB drives.

You will also benefit from Panda Rescue Kit, created to restore your system from virus infections and boot the PC from a clean USB drive.

Regarding Android and Mac devices, the software offers real-time protection against digital threats and scans your apps or programs before installation.

Let’s quickly look at its key features:

  • No impact on system resources
  • Firewall support for Windows devices
  • Wi-Fi network protection
  • Scans USB drives, and external devices

Benefit from all the valuable security functionalities and secure all desktop and mobile devices with Panda Free Antivirus.

Panda Security

Stay protected 24/7 using this freeware antivirus tool with cloud tools and minimal system impact.

Avast – Most known for high network protection

With Avast Free Antivirus, you can have innovative and latest security tools in order to defend your PC from dangerous online threats.

This antivirus comes with a high detection rate and scans every program or software before installing it into your system.

With the CyberCapture feature, you can analyze every file on your computer in the cloud and erase the ones that contain malware or phishing threats.

You can also detect the vulnerable points in your network connection and prevent attackers from compromising your PC or stealing sensitive information.

Let’s look at its main features:

  • Blocks viruses and advanced malware
  • Detect malicious and fake website
  • Blocks remote access attacks
  • 30 days money-back guarantee
  • Compatible with Windows, Mac, and mobile systems

Avast security solutions will benefit any user with high detection rates and multi-layered protection from digital threats.


Utilize this comprehensive antivirus with anti-tracking features and SecureLine for online privacy.

Kaspersky Standard– Best for PC optimization

Kaspersky antivirus is free-to-use software that entirely safeguards your PC against multiple threats from your digital environment.

This complete solution offers protection from common threats like spyware or malware and more complex virus types like file-less attacks.

Plus, you have reliable protection against phishing attacks and elaborated social engineering threats present online.

You can therefore secure your digital presence against advanced email scams, malicious websites, and all types of malware out there.

Let’s quickly look at its key features:

  • Optimized system performance
  • High protection functionalities
  • Online banking or shopping data protection
  • Simple to use interface
  • Available for Windows, Mac, or mobile devices

With Kaspersky antivirus tools, you’re secured against advanced malware or spyware attacks, so you don’t need to hesitate about it.

Kaspersky Standard

Have a try and encrypt your online data with this enhanced antivirus choice.
Free trial Visit website

AVG Antivirus Free – Best for scam email defense

AVG Antivirus Free is a highly awarded antivirus solution designed to secure any PC from Internet threats, ransomware, or hijacking attempts.

Using this free antivirus, you have unlimited security against risky threats present online, such as viruses and spyware or email phishing attacks.

You can cover your digital presence and avoid dangerous email attacks with the web shield and email shield tools.

Plus, assure your Internet security for maximum protection against ransomware and scams created to infect the PC and steal important personal data.

Besides, stop a billion cyberattacks using competitive threat detection network tools with AVG Antivirus.

Let’s look at its main features:

  • Ransomware and webcam safeguarding
  • Phishing attacks detection engine
  • Android antivirus protection for mobile
  • Real-time updates from an extensive virus database

You can employ AVG antivirus tools without a doubt and defend your system against emerging ransomware or malware threats.


Shield your digital life with this top-notch privacy tool that contains all the security you need.

Emsisoft Anti-Malware Home – Best for increased scanning capability

Emsisoft Anti-Malware main window

Emsisoft Anti-Malware is innovative antivirus software that will constantly monitor your system and detect any unusual programs or activities.

This antivirus solution promises comprehensive security against digital dangers, such as ransomware attacks from unpatched software or corrupted bots, banking trojans, and many more.

You have strong security regarding personal web activities and constant guarding regarding malicious websites and links. Using the browser extension, you’ll be alerted about every suspected website.

Last but not least, Emsisoft antivirus defends you from email phishing attacks and secures personal or sensitive data from elaborate dangers.

Let’s look at its main features:

  • Protection from unsafe websites and links
  • Portable Emergency Kit
  • Anti-phishing emails guarding
  • Latest virus behavior detection
  • A management console for all your devices

Hence, if you require advanced antivirus technology to guard your device against harmful malware, this free antivirus deserves a try.

Emsisoft Antivirus

Enhance your PC malware protection with this niche antivirus software with practical tools.
Free trial Visit website

ClamWin Free Antivirus – A reliable open-source option

If you intend on getting an open-source antivirus software, ClamWin would be the next best thing after ClamAV. Though it offers limited features, the antivirus is trusted by users worldwide owing to enhanced compatibility, making it one of the best open source antivirus for Windows 10.

Based on the ClamAV engine, ClamWin has an easy installation setup and a user-friendly interface to perform actions effortlessly and seamlessly.

Here are some of the key features of ClamWin:

  • Highly effective at identifying malware and virus
  • Automatically downloads any new additions to the threat database
  • Can be used to scan files right from the context menu
  • Has an add-in for Outlook to scan attachments

When it comes to open-source antivirus, ClamWin finds a place in the top options.

Get ClamWin Free Antivirus

What is an open-source antivirus?

An open-source antivirus is security software developed by multiple programmers that constantly improve the source code.

These types of antivirus tools can be used for free to protect your PC from various online threats like malware or spyware.

Why use an open-source antivirus?

You can utilize open-source antivirus programs for multiple security needs, such as spam threats, phishing attacks through emails, malicious websites or URLs, banking data attacks, and so on.

There are certain security flaws you should be aware of when you utilize open-source tools.

For instance, it can be an opportunity for hackers and attackers to exploit the software. The fact that any individual can modify the public code of the software is a vulnerability for users as well.

The attackers can access all the information about the software and exploit it for personal benefit.

If interested, check out our guide on Antivirus statistics to know more about the importance of security tools.

Main advantages of open-source software

Here are some of the core benefits of using an open-source antivirus in Windows:

  • Open-source tools are more convincing, given the transparency concerning data for anyone to see
  • The security issues are patched or fixed quickly
  • The community constantly examines open-source tools
  • Extensive flexibility for users
  • Open-source software with active communities is more sustainable

Disadvantages of open-source antivirus

Even though you can rely on some open-source antivirus solutions, there are a few weak points you should know about:

  • The code of the software is made public to any user.
  • Volunteers or programmers build open-source antivirus without fixed schedules.
  • Cybercriminals can profit from security concerns with false open-source tools.
  • The open-source antivirus is difficult to be maintained on the cloud.

Speaking of such programs, we have a list of antivirus software with lifetime licenses for you to check out. All of them are great, offering robust sets of features. Even more, note that these solutions can help you too when facing the Windows Error Code 0x800700E1: Virus Detected.

If you have any other suggestions for this list, don’t hesitate to leave them in the comments section below.

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