Best free antivirus for Windows in 2026
A solid antivirus remains an important part of computer security. The good news is that in 2026 you do not necessarily need to pay for a security suite to get competent protection against viruses, trojans, ransomware, and other types of malware.
Windows 11 itself already includes Microsoft Defender Antivirus, built into the Windows Security app. Beyond that, Bitdefender, Avast, AVG, and Avira still offer free options for home users.
In this guide, we compare five of the main free options available for Windows, looking at protection, ease of use, features included without payment, and results from independent labs.
Catalog: Security & Internet. Guide: safe download.
Summary: which free antivirus should you choose?
| Antivirus | Main advantage | Best for |
|---|---|---|
| Microsoft Defender | Already built into Windows | Most people |
| Bitdefender Free | Simplicity | Defender alternative |
| Avast Free | More features | Users who want extras |
| AVG Free | Easy to use | Beginners |
| Avira Free | Suite with utilities | Users who want multiple tools |
No antivirus can guarantee 100% security. Choosing a product is only one part of protection: an updated system, an updated browser, two-factor authentication, backups, and awareness of scams remain essential.
1. Microsoft Defender — best for most people
Microsoft Defender Antivirus is the simplest option for Windows 11 users. It is part of the Windows Security app and starts protecting your computer without requiring you to download another antivirus.
According to Microsoft, Windows Security includes Microsoft Defender Antivirus, Windows Firewall, and other features that work together to provide real-time protection against viruses, malware, and other threats.
Key features
- real-time antivirus protection;
- quick, full, and custom scans;
- automatic security intelligence updates;
- cloud-based protection;
- protection against potentially unwanted applications;
- threat quarantine;
- ransomware protection features;
- integration with other Windows security layers.
How did it perform in tests?
In the AV-TEST evaluation run in May and June 2026 on Windows 11, Microsoft Defender Antivirus Consumer 4.18 received 6/6 in protection, 5.5/6 in performance, and 6/6 in usability.
| Category | Score |
|---|---|
| Protection | 6.0 / 6.0 |
| Performance | 5.5 / 6.0 |
| Usability | 6.0 / 6.0 |
Pros
- already installed on Windows;
- no separate payment required;
- deep system integration;
- automatic updates;
- does not try to sell a "Premium" edition of the antivirus itself;
- excellent recent protection results.
Cons
Defender is less focused on offering a large collection of extras. If you want a VPN, cleanup tools, identity monitoring, or other features, you may prefer a third-party suite.
Recommended for: anyone who wants a simple, built-in solution without installing additional software.
Official site: Windows Security →
2. Bitdefender Antivirus Free — a simple Defender alternative
Bitdefender Antivirus Free is a good option if you want a third-party antivirus without necessarily installing a feature-heavy suite.
The official page says the free edition provides basic protection for Windows, with no time limit and no credit card required. The company also describes protection against threats such as ransomware, infected downloads, phishing, zero-day exploits, rootkits, trojans, and malicious websites.
Key features
- real-time protection;
- malware and suspicious behavior detection;
- basic ransomware protection;
- protection against malicious pages and phishing;
- infected download detection;
- quarantine and information about blocked threats.
What is left out?
Bitdefender's own comparison makes clear that several additional features are reserved for paid products. That is not necessarily a downside: if you only want a third-party antivirus layer, a lean edition may be exactly the goal.
Pros
- simple approach;
- real-time protection;
- free version with no expiration date;
- no credit card required;
- a solid alternative to Microsoft's built-in software.
Cons
- many features stay in paid versions;
- you need to install another program;
- some tests published online may refer to paid suites, not the Free edition.
Recommended for: people who want a relatively simple third-party antivirus.
Official site: Bitdefender Antivirus Free →
3. Avast Free Antivirus — best if you want more features
Avast is one of the best-known names among free antivirus products. In 2026, its free Windows offer still includes real-time protection and several additional security features.
The official page highlights protection against viruses and other malware, file and download analysis, browsing and email security, anti-scam features, and Wi-Fi network checks.
AV-TEST result
Avast Free Antivirus 26.4 and 26.5 received the maximum possible score in the May and June 2026 test:
| Category | Score |
|---|---|
| Protection | 6.0 / 6.0 |
| Performance | 6.0 / 6.0 |
| Usability | 6.0 / 6.0 |
In the zero-day threat protection test, including web and email threats, AV-TEST recorded 100% protection in May and 99.8% in June for this Avast version. Detection of the prevalent malware set was 100% in both months.
Pros
- excellent recent independent lab result;
- real-time protection;
- several security features;
- protection related to the web, downloads, and email;
- official free version.
Cons
Avast uses a freemium model. That means you will see paid product features and offers inside the company's ecosystem. If you only want a discreet antivirus, that may be less appealing than using Defender.
Recommended for: people who want more features and do not mind offers for additional services.
Official site: Avast Free Antivirus →
4. AVG AntiVirus Free — easy to use and highly rated
AVG AntiVirus Free is another traditional option for Windows. According to the company, the free edition offers real-time protection against viruses, infected emails, fraudulent websites, dangerous downloads, and other threats.
AV-TEST result
AVG Antivirus Free 26.4 and 26.5 also received 6/6 in all three categories evaluated in June 2026:
| Category | Score |
|---|---|
| Protection | 6.0 / 6.0 |
| Performance | 6.0 / 6.0 |
| Usability | 6.0 / 6.0 |
Recent results have been consistent: AVG Free also scored 6/6/6 in the April 2026 test. In February, it scored 6 in protection, 5.5 in performance, and 6 in usability.
AVG or Avast?
For most people, it does not make sense to install both. Besides occupying a very similar place in the market, AVG and Avast belong to the same group, Gen Digital, which also includes brands such as Norton and Avira.
In practice, choosing between AVG and Avast may depend more on the interface and the specific features you prefer than on a huge difference in basic protection.
Pros
- excellent recent AV-TEST result;
- real-time protection;
- relatively simple interface;
- protection related to files, the web, and email.
Cons
- some features require paid products;
- may show offers for additional services;
- users already happy with Defender may not gain much by switching.
Recommended for: people who want a traditional, easy-to-use antivirus.
Official site: AVG AntiVirus Free →
5. Avira Free Security — for those who want a free suite
Avira Free Security takes a broader approach. Instead of offering only an antivirus, it brings together security, privacy, and maintenance functions in one app.
The official page presents features such as full virus scans, quarantine, protection options, smart scanning, and a software updater. The company also offers additional privacy and performance tools within the suite, with differences between free and paid tiers.
Pros
- antivirus and other tools in the same app;
- malware scans;
- quarantine;
- software updater;
- additional privacy and performance tools.
Cons
- several additional features have limits in the free edition;
- the suite can feel excessive if you only want antivirus;
- advanced features are reserved for Avira Prime and other paid products.
Recommended for: people who prefer to keep several security and maintenance tools in one program.
Official site: Avira Free Security →
AV-TEST results for June 2026
AV-TEST evaluated 16 security products for home users on Windows 11 during May and June 2026. Each product can receive up to 6 points in three categories: protection, performance, and usability.
Among the options in this list that were tested directly in their free or built-in versions, the results were:
| Product | Protection | Performance | Usability |
|---|---|---|---|
| Avast Free | 6 | 6 | 6 |
| AVG Free | 6 | 6 | 6 |
| Microsoft Defender | 6 | 5.5 | 6 |
Bitdefender Total Security and Avira Internet Security were also evaluated and appear in the report, but they are different products from the free versions highlighted in this article.
A lab score is useful, but it should not be read as a promise of absolute protection. Tests represent specific scenarios and product versions.
Is Microsoft Defender enough in 2026?
For many home users, yes.
The idea that the antivirus built into Windows is necessarily weak protection does not match today's landscape well. In the June 2026 test, Defender earned AV-TEST's maximum protection score.
Microsoft also maintains several security layers inside Windows, such as real-time protection, file scanning, updated security intelligence, and integration with other system components.
That is why you do not need to automatically install Avast, AVG, or another antivirus as soon as you set up a new computer.
A third-party product can make sense if you:
- prefer another interface;
- want specific extra features;
- already use other services from the same company;
- want a suite that brings different tools together.
For anyone who wants simplicity, updated Windows + Microsoft Defender + good security habits is a reasonable combination.
Is free antivirus safe? And is it worth paying?
A legitimate free antivirus can be safe. The essential point is to use an official version provided by the manufacturer itself.
The freemium model usually works like this: the company provides basic protection for free and offers commercial plans with more features.
Paid plans may add functions such as:
- VPN;
- identity and breach monitoring;
- protection for multiple devices;
- parental controls;
- advanced ransomware features;
- additional privacy tools;
- expanded technical support.
Those features can be useful, but that does not mean every home user needs a subscription. If your need is mainly malware protection, it is worth starting by evaluating a free option.
Can I use two antivirus programs at the same time?
In general, it is not recommended to keep two primary antivirus products running real-time protection at the same time.
The programs may try to analyze the same files, interfere with each other, generate confusing alerts, or waste system resources.
Microsoft notes that when a non-Microsoft antivirus or antimalware product is running, Microsoft Defender Antivirus can automatically enter a disabled mode. After you remove the other software, Defender should return to active mode.
Does antivirus slow down your computer?
Every antivirus uses some computer resources. It monitors files, runs scans, queries online services, and analyzes activity in the background.
On modern machines, the impact is usually small in day-to-day use, but it can vary depending on the hardware and the product you choose.
That is exactly why labs such as AV-TEST have a specific performance category. In the June 2026 test, Avast Free and AVG Free scored 6/6 in performance, while Defender scored 5.5/6.
Watch out for fake antivirus, cracks, and "free Premium"
Download security software only from the official site.
Avoid searches and downloads such as:
- "antivirus premium crack";
- "Bitdefender free key";
- "Avast Premium activated";
- "antivirus serial 2026";
- "full antivirus torrent".
Cracks, keygens, and modified installers can be used to distribute exactly the kind of malware an antivirus is supposed to stop.
Avast itself maintains a page explaining that it offers official free versions and recommending that users avoid cracks, keygens, and illegal downloads.
See also our guide: how to download free software safely.
Antivirus alone does not protect against everything
Many current threats do not depend only on installing malware. Scams may try to convince the victim to hand over a password, authentication code, or banking details.
To improve your security:
- Keep Windows updated. Updates fix system vulnerabilities.
- Update your browser and apps. Old programs can also contain security flaws.
- Use two-factor authentication. Especially for email and important accounts.
- Do not reuse the same password. A breach on one service should not compromise all the others.
- Make backups. They help against ransomware, hardware failures, and accidental deletions.
- Be suspicious of urgency. Scammers often try to make the victim act without thinking.
- Download programs from trusted sources. Always prefer the official developer.
Microsoft recommends using up-to-date antivirus, installing apps only from trusted sources, and keeping Windows, your browser, and other programs updated.
What about people still using Windows 10 in 2026?
Here there is a bigger issue than choosing between Defender, Avast, AVG, or Bitdefender.
Regular support for Windows 10 ended on October 14, 2025. Microsoft states that after that date, the system stopped receiving technical assistance, feature updates, and regular security updates.
A Windows 10 PC still works, but without security updates or another form of support, it becomes more exposed to new vulnerabilities.
If the computer is compatible, Microsoft recommends upgrading to Windows 11. For certain computers that remain on Windows 10, there is also the Extended Security Updates (ESU) program.
Microsoft: end of Windows 10 support →
What is the best free antivirus of 2026?
Best overall: Microsoft Defender
It is our recommendation for most users because it is already built into Windows, does not require another install, and showed excellent protection in recent tests.
Best simple alternative: Bitdefender Antivirus Free
A good option if you prefer a third-party antivirus focused on basic protection.
Best for features: Avast Free Antivirus
Interesting if you want more tools, and it earned a perfect score on the June 2026 AV-TEST.
Easy-to-use alternative: AVG AntiVirus Free
Also scored 18/18 on AV-TEST and offers a traditional antivirus experience.
Best free suite: Avira Free Security
Aimed at people who prefer antivirus and other tools together in the same app.
Frequently asked questions
Does Windows 11 already include antivirus?
Yes. Windows 11 includes Microsoft Defender Antivirus inside the Windows Security app.
Do I need to install Avast or another antivirus on a new PC?
Not necessarily. If Microsoft Defender is active and up to date, the computer already has an antivirus solution.
Is Microsoft Defender free?
Yes. Microsoft Defender Antivirus built into Windows does not require a separate subscription.
Is Bitdefender Free really free?
According to Bitdefender's official page, the Free version is free, has no hidden time limit, and does not require a credit card.
Is Avast Free really free?
Yes. Avast offers an official free version for Windows. Additional services and features may be offered separately.
Does AVG Free protect in real time?
Yes. AVG states that its free edition offers real-time protection against viruses, email threats, fraudulent websites, and other risks.
Does Avira still offer free protection?
Yes. Avira Free Security remains available for free, with antivirus and additional tools, although some advanced features are paid.
Which free antivirus scored highest on AV-TEST?
In the June 2026 test, Avast Free Antivirus and AVG Antivirus Free received 6/6 in protection, 6/6 in performance, and 6/6 in usability. Microsoft Defender received 6/6 in protection, 5.5/6 in performance, and 6/6 in usability.
Conclusion
Choosing a free antivirus for Windows is simpler than it looks.
For most Windows 11 users, Microsoft Defender is already a competent option, and there is no need to automatically install a third-party antivirus.
If you want an alternative, consider Bitdefender Antivirus Free. Avast and AVG are solid options if you want more features and had excellent results on the June 2026 AV-TEST. Avira Free Security may appeal to people who prefer a suite with several tools together.
Regardless of your choice, security works best in layers:
updated antivirus + updated system + updated programs + unique passwords + two-factor authentication + backups + awareness of scams.
And remember: never download "unlocked Premium" versions, cracks, or installers from unknown sites. When an official free version exists, always use the manufacturer's site.
Official links
- Microsoft Defender / Windows Security
- Bitdefender Antivirus Free
- Avast Free Antivirus
- AVG AntiVirus Free
- Avira Free Security