5 Best Free Antivirus 2026: 99%+ Detection (Actually Free)

Here’s a question that would have been absurd a decade ago: Is free antivirus good enough in 2026?

The surprising answer is yes—for most people. Windows Defender, once a punchline among security professionals, now scores alongside paid solutions in independent testing. Several free third-party options offer legitimate protection without the aggressive upselling that plagued earlier generations of freemium antivirus.

But “good enough” comes with caveats. Free antivirus lacks features that matter: ransomware protection, identity monitoring, secure browsers for banking. Some free options monetize your data in ways that undermine the security they claim to provide.

We tested the major free antivirus options against real-world threats and independent lab results to separate genuine protection from marketing theater. Here’s what actually keeps you safe without opening your wallet.

Quick verdict: Windows Defender is genuinely good enough for careful users. Bitdefender Free offers the best third-party free protection. Avast/AVG provide solid protection but with privacy tradeoffs you should understand.

Quick Comparison: Best Free Antivirus 2026

Is Free Antivirus Good Enough?

Before diving into specific products, let’s address the fundamental question: should you trust free antivirus with your security?

The Case for Free Antivirus

Windows Defender has genuinely improved. In AV-TEST’s 2025 evaluations, Windows Defender consistently scored 5.5-6/6 for protection—matching or exceeding many paid solutions. Microsoft’s massive telemetry network (data from millions of Windows installations) feeds its threat detection, and the company has invested heavily in security since the early 2010s.

Core protection is commoditized. The basic task of detecting known malware is largely solved. Signature databases are shared across the industry, and most reputable antivirus—free or paid—catches 99%+ of known threats. The differentiation happens in zero-day detection, where the gaps between free and paid are narrower than marketing suggests.

Free tiers fund paid development. Companies like Bitdefender and Avast offer free versions as marketing for their premium products. They’re incentivized to provide genuine protection—a free antivirus that fails publicly damages the brand.

The Case Against Free Antivirus

You’re missing features that matter. Real-time ransomware protection, secure browsers, identity monitoring, VPNs, password managers—these extras bundled in paid suites provide genuine value. The $30-50/year for a paid suite often costs less than recovering from one successful attack.

Privacy tradeoffs are real. Some free antivirus products collect and sell anonymized user data. Avast made headlines in 2020 for selling browsing data through a subsidiary called Jumpshot. They shut down the practice after public backlash, but the incentives remain for free products.

Support is minimal. When something goes wrong—a false positive quarantines an important file, or you suspect an infection—free users wait in line behind paying customers. Sometimes there’s no support at all.

Protection gaps exist. While core malware detection is similar, paid versions often include better anti-phishing, exploit protection, and behavioral analysis. These advanced features catch threats that signature-based detection misses.

The Bottom Line

For careful users who practice good security hygiene—avoiding suspicious downloads, keeping software updated, not clicking random email links—Windows Defender or a quality free third-party antivirus provides adequate protection. For users who want comprehensive protection, prefer peace of mind, or regularly engage in higher-risk activities (downloading torrents, visiting unfamiliar sites), paid antivirus is worth the investment.

Best Free Antivirus: Detailed Reviews

1. Windows Defender (Microsoft Defender) — Best for Most Users

The security product Microsoft bundles with Windows has transformed from a joke into a genuine contender. In AV-TEST’s November 2025 evaluation, Windows Defender achieved a 17.5/18 score—just half a point behind Bitdefender and Norton. That’s remarkable for a free, pre-installed solution.

What’s actually good:

Windows Defender runs constantly in the background with negligible performance impact on systems from the last five years. The real-time protection scans downloads, monitors running processes, and checks files as they’re accessed. Cloud-delivered protection uploads suspicious file samples to Microsoft’s servers for analysis, enabling faster response to new threats.

The integration with Windows is seamless because, well, it’s the same company. Windows Security Center provides a unified dashboard for antivirus, firewall, app security, and device health. SmartScreen protection blocks malicious websites and downloads in Edge and other Microsoft apps. Controlled Folder Access (disabled by default) prevents unauthorized apps from modifying files in protected folders—useful ransomware protection if you enable it.

What’s genuinely limited:

Controlled Folder Access—the ransomware protection feature—requires manual configuration and can be annoying, blocking legitimate apps until you whitelist them. Most users leave it disabled, eliminating one of Defender’s best features.

Phishing protection works best in Microsoft Edge. If you use Chrome or Firefox, you lose some SmartScreen capabilities. The browser-based protection that Bitdefender and Norton provide across all browsers doesn’t exist in Defender’s free version.

There’s no VPN, no password manager, no identity monitoring, no secure browser for banking. If you want those features, you need to source them separately or pay for Microsoft 365, which includes some premium Defender features.

The performance reality:

In AV-Comparatives’ performance testing, Windows Defender ranked in the middle of the pack. It’s noticeably heavier than Bitdefender or Kaspersky during full scans but handles real-time protection efficiently. On an SSD-equipped system with 8GB+ RAM, you won’t notice it running.

Bottom line: Windows Defender is good enough for the majority of Windows users. Its transformation from liability to legitimate protection is one of the bigger reversals in the security industry. For most people, especially those who don’t want to think about antivirus, it’s the right choice.

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2. Bitdefender Antivirus Free — Best Third-Party Free Protection

Bitdefender’s free antivirus uses the same detection engine that powers their paid products—the engine that consistently tops independent testing charts. In AV-TEST evaluations, Bitdefender achieves perfect 6/6 scores for protection with remarkable consistency.

What you get for free:

The core Bitdefender engine runs in “Autopilot” mode, making decisions automatically without pestering you. Real-time protection scans files on access. Web protection blocks malicious URLs across all browsers, not just a specific one. Anti-phishing detection catches fake login pages and scam sites.

The interface is minimal by design—Bitdefender’s free tier assumes you want protection without complexity. There’s essentially one setting: on or off. Scans run automatically in the background. Threats are handled without asking you to make decisions you’re not qualified to make.

What you don’t get:

The ransomware remediation that makes paid Bitdefender special isn’t included. Neither is the SafePay secure browser, the vulnerability scanner, the file shredder, or the limited VPN. You also lose the firewall, webcam protection, and parental controls.

Perhaps most significantly, you miss Bitdefender’s multi-layer ransomware protection that monitors for suspicious encryption behavior. Free users get basic detection of known ransomware but not the behavioral analysis that catches new variants.

The privacy picture:

Bitdefender collects anonymized telemetry data to improve threat detection—standard practice for security software. They don’t sell this data to advertisers or operate in the ethically murky territory some competitors have explored. Their privacy policy is straightforward by industry standards.

Bottom line: If Windows Defender doesn’t satisfy you and you want genuine, lab-tested protection without paying, Bitdefender Free is the answer. The protection quality matches or exceeds every paid antivirus we’ve tested except Bitdefender’s own paid tiers.

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3. Avast Free Antivirus — Most Features for Free

Avast popularized the freemium antivirus model, and their free version remains one of the most feature-complete options available. Beyond core protection, you get a Wi-Fi inspector that scans your network for vulnerabilities, a software updater that checks for outdated applications, and browser cleanup tools.

The feature set:

Real-time protection scans files, email attachments, and web traffic. The behavior shield monitors running programs for suspicious activity. CyberCapture uploads unknown files to Avast’s cloud for analysis. The Wi-Fi Inspector scans your network for weak passwords, unauthorized devices, and router vulnerabilities—genuinely useful for home network security.

The software updater identifies programs with available security patches. Browser cleanup removes unwanted toolbars and extensions. These aren’t core antivirus features, but they address real security risks that other free options ignore.

The elephant in the room:

In January 2020, a joint investigation by Motherboard and PCMag revealed that Avast had been collecting and selling detailed user browsing data through a subsidiary called Jumpshot. The data was supposedly anonymized but contained enough detail to potentially identify individuals. Avast shut down Jumpshot shortly after the revelations.

Should you trust Avast after this? The company has changed practices, become more transparent about data collection, and faced regulatory consequences. But the incident revealed what free antivirus companies are tempted to do, and trust once broken is hard to rebuild.

System impact:

Avast runs heavier than Windows Defender or Bitdefender Free. You’ll notice longer boot times and occasional slowdowns during scans. On older systems or machines with limited RAM, this matters. On modern hardware, it’s acceptable but not invisible.

The upselling:

Avast displays frequent prompts to upgrade to paid products. These aren’t malicious, but they’re annoying. Expect regular reminders that you’re “not fully protected” without premium features. The dark patterns aren’t egregious, but they’re present.

Bottom line: Avast Free offers genuine protection and useful extra features. The privacy history is concerning but addressed. If you can tolerate the upselling and don’t mind the privacy tradeoffs, it’s a capable free solution—but Bitdefender Free offers similar protection without the baggage.

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4. AVG AntiVirus Free — Same Engine, Different Paint

Here’s a secret the antivirus industry doesn’t advertise: AVG and Avast merged in 2016. Both products now use the same detection engine under different interfaces. Choosing between them is like choosing between different colors of the same car.

What you get:

AVG’s detection capabilities mirror Avast’s exactly—they share the same virus definitions and scanning technology. The free tier includes real-time protection, email scanning, link protection, and basic ransomware detection. AVG also includes a file shredder for secure deletion, which Avast reserves for paid tiers.

The interface is cleaner and arguably more professional than Avast’s. Some users prefer its layout. Performance characteristics are identical since the underlying engine is the same.

Why it exists:

Brand recognition. AVG had an established user base before the merger. Discontinuing it would lose customers who might not migrate to Avast. So both brands continue, targeting slightly different user preferences with the same core product.

Privacy and upselling:

Same parent company means same privacy history and same data practices. The Jumpshot scandal implicated both brands. Upselling is similarly aggressive, with regular prompts to upgrade to paid protection.

Bottom line: AVG is effectively Avast with a different interface. If you prefer AVG’s look, use it. If you prefer Avast’s extra features like Wi-Fi Inspector, use that. There’s no meaningful security difference between them.

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5. Malwarebytes Free — Best Second-Opinion Scanner

Malwarebytes Free isn’t trying to be your primary antivirus. It’s an on-demand scanner designed to run alongside Windows Defender or another solution, catching threats that slip through.

The use case:

Run Malwarebytes when you suspect something’s wrong, when you’ve downloaded something questionable, or as a monthly checkup. It excels at finding adware, potentially unwanted programs (PUPs), and malware that embeds itself deeply in systems. IT professionals routinely use it for malware removal after infections.

What free means here:

The free version provides scanning and removal only. No real-time protection—threats aren’t caught as they arrive. You must manually initiate scans. The program doesn’t run in the background or protect you proactively.

This limitation makes Malwarebytes Free unsuitable as standalone protection. But it makes the program perfectly complementary to Windows Defender or another antivirus. There are no conflicts because there’s no real-time component fighting for resources.

Detection specialization:

Malwarebytes focuses on different threat categories than traditional antivirus. It’s particularly effective against adware, browser hijackers, and the “gray area” programs that aren’t quite malicious but aren’t wanted either. These PUPs often evade traditional antivirus designed for clear-cut malware.

The paid upgrade:

Malwarebytes Premium adds real-time protection, exploit protection, and ransomware protection. It can serve as a standalone antivirus, though independent testing shows detection rates below Bitdefender or Windows Defender. The company positions Premium as an addition to Windows Defender rather than a replacement.

Bottom line: Keep Malwarebytes Free on hand for occasional scans. It’s the tool you want when you think something’s wrong or when you need a second opinion. But don’t rely on it alone—pair it with Windows Defender or another real-time solution.

Free Antivirus to Avoid

Not every free antivirus deserves your trust. Some products create more problems than they solve.

Kaspersky — Geopolitical Concerns

Kaspersky’s detection capabilities are genuinely excellent—among the best in independent testing. The problem isn’t technical. In 2017, the U.S. government banned Kaspersky products from federal systems over concerns about Russian government influence. Germany issued similar warnings in 2022 after Russia’s invasion of Ukraine.

Is Kaspersky actually compromised? No smoking gun has emerged publicly. But security software requires trust, and that trust is difficult to extend to a company headquartered in Moscow with potential government ties. Unless you have specific reasons to choose Kaspersky, alternatives without geopolitical baggage offer equivalent protection.

Norton 360 Free Trial — Not Actually Free

Norton doesn’t offer a genuinely free antivirus tier. Their “free” option is a 7-day trial of Norton 360 that requires credit card information and auto-enrolls you in a paid subscription. This isn’t inherently predatory—trials are legitimate—but it’s not free antivirus in the way Windows Defender or Bitdefender Free are free.

”Antivirus” Apps with No Reputation

App stores contain hundreds of free “antivirus” apps from unknown developers. Many do nothing useful. Some are actually malware themselves, requesting permissions to access your files and data under the guise of scanning them. Stick to established brands with verifiable track records and independent testing results.

What You Miss Without Paid Antivirus

Free antivirus handles basic malware detection well. Here’s what upgrading adds:

Ransomware Protection

Free antivirus detects known ransomware signatures. Paid versions add behavioral monitoring that catches ransomware by watching for suspicious encryption activity. When ransomware locks your files, paid solutions can sometimes restore them from protected backups. Free versions can only warn you after the damage is done.

Identity Monitoring

Paid suites increasingly include dark web monitoring, credit monitoring, and identity theft insurance. When your email appears in a data breach, you’re notified. If someone opens accounts in your name, you have resources to respond. Free antivirus provides none of this.

VPN and Password Manager

Norton, Bitdefender, and McAfee bundle VPNs and password managers into their premium tiers. These aren’t best-in-class standalone products, but they’re adequate and included in your subscription. Sourcing these separately often costs more than the antivirus bundle.

Secure Browser for Banking

Features like Bitdefender’s SafePay create isolated browser environments for financial transactions. Keyloggers, screen capture malware, and man-in-the-browser attacks are blocked. Free antivirus offers no equivalent protection for sensitive transactions.

Multi-Device Coverage

Free antivirus typically covers one device or has feature limitations across platforms. Paid suites cover 5-10+ devices including Windows, Mac, iOS, and Android. For households with multiple devices, the per-device cost of premium protection becomes negligible.

Customer Support

When free antivirus quarantines an important file or fails to remove an infection, you’re searching forums for answers. Paid subscribers get live chat, phone support, and priority email response. The value of support becomes obvious when you need it.

How We Evaluated Free Antivirus

Our assessment combined independent lab testing data with practical evaluation:

Independent Testing (60% of assessment): We analyzed results from AV-TEST, AV-Comparatives, and SE Labs—the three most respected independent testing organizations. These labs test against both widespread malware (extensive signature databases) and zero-day threats (new malware without signatures). Detection rates, false positive rates, and system impact were all considered.

Feature Analysis (20% of assessment): What does free actually include? We documented real-time protection, web protection, email scanning, and bonus features. We noted what’s reserved for paid tiers and how aggressively free users are pushed to upgrade.

Privacy and Business Model (20% of assessment): How does the free product make money? We reviewed privacy policies, investigated data collection practices, and assessed whether the business model creates incentive misalignment with user interests. The Avast/Jumpshot situation informed our analysis.

Performance Testing: We installed each free antivirus on identical Windows 11 systems and measured boot time impact, memory usage, and scan duration. Results informed our recommendations for older systems.

We did not accept payment from any antivirus vendor. Our affiliate links generate revenue when readers upgrade to paid products, but our rankings prioritize free tier quality regardless of affiliate availability.

Frequently Asked Questions

Frequently Asked Questions

Is Windows Defender enough for antivirus in 2026?

For most users, yes. Windows Defender scores 17.5/18 in AV-TEST evaluations—matching or exceeding many paid alternatives. If you practice reasonable security habits (avoiding suspicious downloads, keeping software updated, not clicking random email links), Defender provides adequate protection. Power users or those wanting features like VPN, password manager, or identity monitoring should consider paid alternatives or supplementing Defender with standalone tools.

What's the best free antivirus for Windows 11?

Windows Defender is already built into Windows 11 and performs excellently. If you want third-party protection, Bitdefender Free offers the highest detection rates among free options. For users wanting more features, Avast Free includes extras like Wi-Fi scanning and software updates, though with more aggressive upselling.

Do free antivirus programs sell your data?

Some do. Avast was caught selling detailed browsing data through Jumpshot in 2020 and shut down the practice after public backlash. Windows Defender collects telemetry that's anonymized and used for threat detection. Bitdefender Free collects minimal anonymized data. Before installing any free antivirus, review their privacy policy and understand how they monetize free users.

Should I use Avast or AVG?

They use the same detection engine since their 2016 merger—protection quality is identical. Avast includes a Wi-Fi inspector and more features. AVG has a cleaner interface and includes a file shredder. Both have the same privacy history concerns. Choose based on interface preference; there's no security difference.

Can free antivirus remove existing viruses?

Yes. Free antivirus from Bitdefender, Avast, and AVG can detect and remove existing infections. For stubborn malware, Malwarebytes Free is particularly effective as a supplementary scanner. If you suspect an active infection, run full scans with multiple tools—malware sometimes evades single scanners.

Is Malwarebytes Free enough protection?

No. Malwarebytes Free provides on-demand scanning only—no real-time protection. It won't catch threats as they arrive. Use it alongside Windows Defender or another real-time antivirus, not instead of one. Malwarebytes excels at finding adware and PUPs that traditional antivirus misses, making it valuable as a second-opinion scanner.

Why would anyone pay for antivirus if free is good enough?

Free antivirus handles basic malware detection well. Paid versions add: ransomware protection with file recovery, identity and dark web monitoring, bundled VPNs and password managers, secure browsers for banking, multi-device coverage (5-10+ devices), and customer support. For users wanting comprehensive protection or peace of mind, the $30-50/year for paid antivirus often costs less than recovering from one successful attack.

Can I run two antivirus programs at once?

Running two real-time antivirus programs causes conflicts—they fight over file access and create performance issues. However, you can run Windows Defender alongside Malwarebytes Free because Malwarebytes Free has no real-time component. For periodic second-opinion scans, temporarily disable your primary antivirus, scan with another tool, then re-enable.

Final Verdict

Best free antivirus overall: Windows Defender. It’s already on your Windows PC, requires zero configuration, and matches paid alternatives in independent testing. For most users practicing reasonable security habits, Defender is genuinely sufficient.

Best third-party free antivirus: Bitdefender Free. If you want dedicated security software beyond what Microsoft provides, Bitdefender offers top-tier detection in a lightweight, no-nonsense package. No concerning privacy history, minimal upselling, and the same engine that powers industry-leading paid protection.

Best supplementary scanner: Malwarebytes Free. Keep it around for periodic checks and suspected infections. It catches what other scanners miss, particularly adware and potentially unwanted programs.

When to pay: If you want ransomware protection that can recover your files, identity monitoring, a bundled VPN and password manager, or coverage for multiple devices, paid antivirus is worth the $30-50 annual investment. Bitdefender Total Security and Norton 360 are our top paid recommendations.

Free antivirus has genuinely improved. The days of needing to pay for basic protection are over. But “basic” has limits—and understanding those limits helps you make the right choice for your security needs.