Best free antivirus for Windows in 2026: top 7 picks

Which free antivirus is best for your PC in 2026? For most Windows 10 and 11 users, it’s the built-in Microsoft Defender: it’s already running, and it scored 17.5 out of 18 in AV-TEST’s May–June 2026 test. If you want a third-party program, pick Bitdefender Antivirus Free to avoid extra notifications, or AVG AntiVirus Free or Avast Free Antivirus, whose free versions earned all 18 points in AV-TEST.

Below are 7 free programs for Windows that are current as of September 2026. For each one: what the free version includes and what it lacks, how often it pushes a paid subscription, what’s known about its data practices, and how it did in the AV-TEST and AV-Comparatives labs. After the list, you’ll find a comparison table, a look at whether Microsoft Defender is enough, and tips on choosing.

How we picked

• Free Windows versions only. Every program can be downloaded from its maker’s website as of September 2026. Trial versions of paid antivirus software didn’t make the list.
• Independent tests with dates. Results come only from AV-TEST and AV-Comparatives. If a lab tested the paid version of a program, we say so.
• Features and limits. What the free version includes and what the paid one adds, based on the makers’ pages as of September 25, 2026.
• Ads and privacy. The makers’ privacy policies, AV-Comparatives’ observations from its 2025 Summary Report, and the U.S. Federal Trade Commission (FTC) order against Avast.
• What didn’t make the cut. Kaspersky Free: Kaspersky products are banned in the U.S., and the company is under sanctions in Ukraine (details in the FAQ at the end). Sophos Home now offers only a 30-day trial, Norton has only a trial period, and the free TotalAV has no real-time protection. 360 Total Security and Comodo appear neither in the latest AV-TEST test nor in AV-Comparatives’ 2026 main test series.

We didn’t test the programs ourselves: the data below comes from the makers and the labs. The list runs from built-in protection to third-party programs, with stronger test results and fewer ads in the free version ranking higher.

1. Microsoft Defender Antivirus

Already in WindowsBuilt-in Windows antivirus

Microsoft Defender Antivirus

Real-time protection

yes

Where to find it

the Windows Security app

AV-TEST, May–June 2026

17.5 out of 18 (protection 6, performance 5.5, usability 6)

AV-Comparatives, February–May 2026

99.0% of attacks blocked, 0 false positives

Included

firewall, SmartScreen, ransomware folder protection

Paid add-on

Microsoft Defender in Microsoft 365 Personal and Family

Windows 11Windows 10

PriceFree, included with Windowschecked 25 September 2026

Baseline protection that’s already on and updates through Windows Update. A good fit for most home PCs, as long as the system gets updates.

Pros

• Nothing to install
• 0 false positives in the Real-World Test
• Updates along with Windows

Cons

• Detected 89.2% of samples offline
• SmartScreen checks sites only in Edge
• Ransomware folder protection is off by default

Microsoft Support

Microsoft Defender Antivirus is built into Windows 10 and 11 and turns on automatically if there’s no other antivirus on the PC or its license has expired. Updates arrive through Windows Update, so there’s nothing to install. Besides the antivirus, the Windows Security app includes a firewall and the SmartScreen filter, and Windows 11 adds phishing protection that warns you if you type your Windows password on a dangerous site.

Defender’s test results and weak spots are covered in the “Is Microsoft Defender enough?” section below. The Microsoft Defender app that comes with Microsoft 365 Personal and Family is a separate paid product; the built-in Windows protection works without it.

2. Bitdefender Antivirus Free

Minimal notificationsFree antivirus

Bitdefender Antivirus Free

Real-time protection

yes

Ransomware protection

basic

VPN

200 MB per day per device

AV-TEST, May–June 2026

18 out of 18 (paid Total Security)

AV-Comparatives, February–May 2026

99.5% (paid Total Security)

Required

Bitdefender Central account

Windows

PriceFree, no time limitchecked 25 September 2026

A no-frills antivirus: according to Bitdefender, it only alerts you about threats and doesn’t show annoying pop-ups. A good fit if you want to install protection and forget about it.

Pros

• Alerts only about threats
• Same tech as paid versions (per Bitdefender)
• Basic VPN with 200 MB per day

Cons

• Requires a Bitdefender Central account
• No file recovery after ransomware
• No vulnerability scan or anti-tracking

Bitdefender website

Bitdefender’s free antivirus is built to be set and forgotten: real-time protection, on-demand scans, blocking of malicious and phishing sites, and basic ransomware protection. It runs on Windows only and never expires, but you need a Bitdefender Central account to install it.

Compared with the paid Antivirus Plus, it lacks file recovery after a ransomware attack, protection from web trackers and social media threats, a scan for outdated software, and a mode that stays out of the way during games and movies. It does include a basic VPN with 200 MB per day. The labs test the paid Bitdefender Total Security, and Bitdefender says the free version uses the same technologies.

3. AVG AntiVirus Free

18 out of 18 in AV-TESTFree antivirus

AVG AntiVirus Free

Real-time protection

yes

Ransomware protection

yes

Email, website and Wi-Fi checks

yes

AV-TEST, May–June 2026

18 out of 18

AV-Comparatives, February–May 2026

99.3%

Interface language

Russian yes, Ukrainian no

License

personal use only

Windows 11108.187

PriceFreechecked 25 September 2026

A free version the labs test directly, built on the same engine as Avast but with low-key ads after installation, according to AV-Comparatives. A good fit if you want strong protection without a subscription.

Pros

• Free version scored 18 out of 18 in AV-TEST
• Protects against ransomware and bad emails
• Warns if your email password leaks

Cons

• Installs AVG Secure Browser during setup
• Webcam protection and firewall are paid-only
• No Ukrainian interface

AVG website

AVG AntiVirus Free provides real-time protection against viruses, ransomware, dangerous emails and scam sites, checks your home Wi-Fi network, and warns you if your email password shows up in a leak. AVG belongs to Gen Digital, the same company as Avast, and according to AV-Comparatives it runs on the Avast engine. That’s why their results match: 18 out of 18 in AV-TEST and 99.3% in the Real-World Protection Test.

The paid AVG Internet Security adds webcam protection, an enhanced firewall and protection from fake banking and shopping sites. The free version is for personal use only. According to AV-Comparatives, AVG asks you to upgrade several times during setup and installs AVG Secure Browser, but after installation the ads are unobtrusive. The Windows app has no Ukrainian interface; Russian is available.

4. Avast Free Antivirus

AI scam checksFree antivirus

Avast Free Antivirus

Real-time protection

yes

Ransomware protection

yes

Email, website and Wi-Fi checks

yes

Also

rescue disk, password leak alerts, Avast Assistant AI helper

AV-TEST, May–June 2026

18 out of 18

AV-Comparatives, February–May 2026

99.3%

Activation

may ask you to renew after 12 months

Windows 11108.187

PriceFreechecked 25 September 2026

Lots of free features and top test scores, but the interface keeps pushing Premium Security. A good fit if you want Wi-Fi, email and suspicious-message checks in one program.

Pros

• Free version scored 18 out of 18 in AV-TEST
• Rescue disk and Wi-Fi checks
• AI helper for suspicious messages

Cons

• Frequent ads for Premium Security
• 2024 FTC order over selling browsing data
• Installs Avast Secure Browser during setup

Avast website

Avast Free Antivirus is now the free tier of the Avast One app. Besides antivirus with ransomware protection, it checks websites and email attachments (Web Guard and Mail Shield), scans Wi-Fi networks, and includes a rescue disk, password leak alerts and the Avast Assistant AI helper, which assesses suspicious messages and offers. In tests, the free version matches AVG: 18 out of 18 in AV-TEST and 99.3% at AV-Comparatives.

Downsides: ads and past data practices. AV-Comparatives notes the free Avast interface constantly promotes Premium Security and other software, and the installer adds Avast Secure Browser. In 2024, the FTC banned Avast from selling browsing data for advertising and ordered it to pay $16.5 million: per the FTC, from 2014 to 2020 its subsidiary Jumpshot sold such data, collected via browser extensions and the antivirus, to over 100 companies.

The paid Premium Security adds protection from fake websites, an advanced firewall, protection for your webcam and browser-saved passwords, a sandbox and automatic app updates. After 12 months, the free version may ask you to reactivate your subscription, at no cost.

5. Avira Free Security

VPN and password managerFree security suite

Avira Free Security

Real-time protection

yes, cloud-based

VPN

500 MB per month

Also

password manager, app and driver updater, cleanup tools

Phishing protection

Avira Browser Safety extension

AV-TEST, May–June 2026

16.5 out of 18 (paid Internet Security)

AV-Comparatives 2026

not tested

WindowsmacOS

PriceFreechecked 25 September 2026

An antivirus with a set of free tools: a VPN, a password manager and an app updater. A good fit if you want everything in one app and don’t mind ads for Avira Prime.

Pros

• VPN with 500 MB per month
• Password manager and app updater
• Maker says it doesn’t sell your data

Cons

• Frequently advertises Avira Prime
• Web and email protection, firewall are in Prime
• Performance 4.5 out of 6 in AV-TEST (paid)

Avira website

Avira Free Security is more than an antivirus. The free suite includes a VPN capped at 500 MB per month, a password manager, an updater for apps and drivers, a browser extension that blocks phishing sites and ads, and disk cleanup tools. Real-time protection is cloud-based: suspicious files are checked in the Avira Protection Cloud.

The paid Avira Prime adds an unlimited VPN, advanced ransomware protection, built-in web and email protection, a firewall and automatic app updates. Like Avast, Avira belongs to Gen Digital; it says it doesn’t sell user data. AV-Comparatives notes that the free version frequently advertises Prime. Avira isn’t in AV-Comparatives’ 2026 main series; the paid Internet Security scored 16.5 out of 18 in AV-TEST, 4.5 of 6 for performance.

6. Panda Free Antivirus

USB drive protectionFree antivirus

Panda Free Antivirus

Real-time protection

yes, cloud-based

VPN

150 MB per day

USB protection

blocks autorun and scans USB drives

Recovery

Panda rescue kit bootable USB drive

AV-Comparatives, February–May 2026

96.5% (paid Panda Dome Advanced)

AV-TEST 2026

not tested

Windows 11108.187

PriceFree, 1 devicechecked 25 September 2026

A cloud-based antivirus with USB drive protection and a small VPN. But in AV-Comparatives’ 2026 tests, the paid Panda posted the weakest results of any program on this list.

Pros

• Blocks malware autorun from USB drives
• VPN with 150 MB per day
• Unobtrusive ads for paid versions

Cons

• 96.5% in Real-World, 27 false positives
• Installer adds Opera by default
• Firewall and Wi-Fi protection are paid-only

Panda Security website

Panda Free Antivirus comes from Panda Security, a WatchGuard Technologies brand. It checks files in the cloud, blocks malware autorun from USB drives and scans them when plugged in, creates a bootable USB drive to clean a PC that won’t start, and includes a VPN with 150 MB per day. Paid Panda Dome plans add a firewall, Wi-Fi protection, safe shopping, parental controls, a password manager and an unlimited VPN.

Ads for paid versions are unobtrusive: AV-Comparatives describes a thin strip atop the window. The installer also adds Opera by default. The main problem is testing: in 2026, AV-Comparatives tested the paid Panda Dome Advanced, which blocked 96.5% of attacks with 27 false positives (a TESTED award, the lowest) and detected 56.1% of samples offline in the Malware Protection Test. Panda isn’t in AV-TEST’s May–June 2026 test.

7. Malwarebytes Free

For a second opinionFree scanner

Malwarebytes Free

Real-time protection

no, Premium only

Threat scanning and removal

manual

Ransomware and phishing protection

Premium only

AV-Comparatives, February–May 2026

98.8% with 39 false positives (paid Premium)

AV-TEST 2026

not tested

WindowsmacOS

PriceFreechecked 25 September 2026

Not an antivirus replacement but a second-opinion scanner: it finds and removes threats when you run a scan yourself. The maker recommends using it alongside Microsoft Defender.

Pros

• Finds and removes threats already on your PC
• Can run alongside Defender

Cons

• No real-time protection
• No ransomware or phishing protection

Malwarebytes website

Malwarebytes Free isn’t a full antivirus but a free scanner: it finds and removes threats when you start a scan yourself. Real-time protection and protection against ransomware, exploits and phishing sites come only with the paid Malwarebytes Premium Security. The maker itself recommends using the free version alongside Microsoft Defender as a second check if you suspect an infection.

AV-Comparatives’ 2026 main test series includes the paid Malwarebytes Premium: it blocked 98.8% of attacks but had 39 false positives, which got its award lowered to STANDARD. If the scanner flags a program you know, double-check the result before deleting the file.

Best free antivirus for PC: comparison

Program	Best for	Key strength	Key weakness	AV-TEST, May–June 2026	AV-Comparatives, February–May 2026
Microsoft Defender	Everyone on Windows 10 and 11	Built in, 0 false positives	Weaker offline	17.5 out of 18	99.0%
Bitdefender Antivirus Free	People who dislike notifications	Alerts only about threats	Requires a Bitdefender account	18 out of 18*	99.5%*
AVG AntiVirus Free	Protection without a subscription	High scores for the free version	No Ukrainian interface	18 out of 18	99.3%
Avast Free Antivirus	Wi-Fi and email checks	Lots of free features	Frequent Premium ads	18 out of 18	99.3%
Avira Free Security	VPN and password manager users	VPN with 500 MB per month	Frequent Avira Prime ads	16.5 out of 18*	not tested
Panda Free Antivirus	USB drive protection	USB protection, 150 MB/day VPN	Weak 2026 test results	not tested	96.5%*
Malwarebytes Free	A second opinion	Removes threats already on the PC	No real-time protection	not tested	98.8%*

Is Microsoft Defender enough?

For a home PC running Windows 11 or Windows 10 that gets updates, usually yes. In May–June 2026, AV-TEST gave Defender 6 out of 6 for protection and usability and its TOP PRODUCT award. In AV-Comparatives’ Real-World Protection Test for February–May 2026, it blocked 396 of 400 attacks with zero false positives, the best result on that measure among the 20 programs tested.

Defender’s weak spots show up in other tests:

• Offline. In AV-Comparatives’ Malware Protection Test (March 2026), Defender detected 89.2% of samples without an internet connection, versus 96.3% for Avast and AVG and 97.6% for Bitdefender. Online, it detected 98.1%: its protection leans heavily on cloud checks.
• Performance. In AV-Comparatives’ Performance Test (April 2026), Defender’s impact score was 12.9, versus 5.5 for Avast and AVG and 9.6 for Bitdefender (lower is better). AV-TEST gave it 5.5 out of 6 for performance.
• Websites. The SmartScreen filter checks sites and downloads in Microsoft Edge. In Chrome, phishing protection comes from the built-in Google Safe Browsing, whose Standard protection is on by default. We compared browsers’ security in our guide to the best browsers.

If you stick with Defender, turn on the Windows Security features that are off by default or easy to miss:

• Controlled folder access: in Virus & threat protection, open Ransomware protection. It stops unknown apps from changing files in Documents, Pictures, Videos and other folders. It’s off by default.
• Potentially unwanted app blocking: in App & browser control, open Reputation-based protection. It stops apps that show ads or mine cryptocurrency before they install.
• Microsoft Defender Antivirus (offline scan): use it if you suspect an infection. Your PC restarts and scans the drive before Windows loads, and the results appear in Protection history.

A third-party free antivirus makes sense if your PC is slow or often offline, or if you want a VPN and a password manager in one app. For a second opinion, a scanner like Malwarebytes Free is enough.

How to choose a free antivirus

Get real-time protection

An antivirus should check files the moment you open or download them, not just when you click a button. The free versions of Malwarebytes and TotalAV don’t do that: they’re scanners for manual checks. All the other programs on this list protect you in real time.

Check which version was tested, and when

AV-TEST and AV-Comparatives publish their results on their websites with test dates. They test the free versions of Avast, AVG and Microsoft, and the paid versions of Bitdefender, Avira, Panda and Malwarebytes. Watch the false positives too: AV-Comparatives lowered the awards for Panda and Malwarebytes because of them, even though both blocked more than 96% of attacks.

Weigh the ads and bundled extras

Free antivirus makers earn money by selling paid versions. According to AV-Comparatives (2025 Summary Report), Avast and Avira often show ads for their paid suites, while AVG and Panda do it unobtrusively. The Avast and AVG installers add their own browsers, and Panda’s adds Opera, so read every setup screen.

Check what the program does with your data

An antivirus sees everything on your PC, so its privacy policy matters as much as test scores. Bitdefender and Avira say they don’t sell user data, but Bitdefender may send marketing emails to your account address unless you opt out. Microsoft Defender can send suspicious files to Microsoft and asks first if a requested file contains personal data; automatic sample submission can be turned off in Virus & threat protection settings.

One antivirus, not two

Microsoft advises against running two antivirus programs at once: if you install a compatible third-party program, Defender turns itself off. For a second opinion, run Malwarebytes Free on demand. You can also turn on Defender’s limited periodic scanning, but Microsoft warns that it uses only a small part of Defender’s capabilities.

An antivirus can’t protect a stolen password

If you typed your password on a phishing site or it leaked from a service, an antivirus can’t help. Keep your passwords in a password manager and turn on two-factor authentication for your email and social media. Download antivirus software only from the makers’ websites; the links are in the cards above.

Sources and methodology

Analysis of public sourcesChecked 25 September 2026

1. AV-TEST — Windows 11 antivirus test, May–June 2026 av-test.org
2. AV-Comparatives — Real-World Protection Test, February–May 2026 av-comparatives.org
3. AV-Comparatives — Malware Protection Test, March 2026 av-comparatives.org
4. AV-Comparatives — Summary Report 2025 av-comparatives.org
5. FTC — Avast order, June 27, 2024 ftc.gov

FAQ

Which free antivirus is best for Windows 11?

If Windows 11 is up to date, start with the built-in Microsoft Defender: it scored 17.5 out of 18 in AV-TEST’s May–June 2026 test. Among third-party free programs, AVG AntiVirus Free and Avast Free Antivirus have the best results (18 out of 18), while Bitdefender Antivirus Free is the pick if you don’t want extra notifications.

Which free antivirus is lightest on your PC?

Of the programs on this list, Avast and AVG slowed the system least in AV-Comparatives’ Performance Test (April 2026), with an impact score of 5.5, followed by Bitdefender (9.6), Panda (11.1) and Microsoft Defender (12.9); Bitdefender and Panda were tested in paid versions. In AV-TEST’s May–June 2026 test, Avast, AVG and the paid Bitdefender scored 6 out of 6 for performance; Defender scored 5.5.

Can I run two antivirus programs at once?

You shouldn’t: Microsoft advises against running two antivirus programs together, and Defender turns itself off when you install a compatible third-party antivirus. For a second check, use the Malwarebytes Free scanner: it doesn’t provide real-time protection, and you start scans yourself.

Do free antivirus programs sell my data?

It depends on the maker. In 2024, the FTC banned Avast from selling browsing data for advertising and required it to pay $16.5 million. Bitdefender and Avira say they don’t sell user data, but read the privacy policy of any antivirus before you install it.

Why isn’t Kaspersky Free on the list?

Under a U.S. Commerce Department decision, Kaspersky has been barred from signing new agreements with U.S. customers since July 20, 2024, and from providing them with updates since September 29, 2024. In Ukraine, Kaspersky Lab is a sanctioned company, as Ukraine’s National Security and Defense Council calls it in its 2025 review of the national cybersecurity system. That’s why we didn’t consider the free Kaspersky.