Quick Answer: Best free antivirus for PC: Windows Defender (6/6 AV-TEST, already installed), Bitdefender Free (lightest, built on a 6/6 AV-TEST-rated engine), Avast Free (6/6 AV-TEST, most features), Malwarebytes Free (best malware removal). Best combination: Windows Defender + Malwarebytes Free.
Cyber threats are more sophisticated than ever in 2026 — but you don’t need to spend money to protect your PC. According to AV-TEST laboratory results published in 2026, several free antivirus programs now score a perfect 6/6 in protection, matching or exceeding many paid alternatives.
This guide reviews the 10 best free antivirus programs for PC based on verified AV-TEST and AV-Comparatives lab results, real-world performance, and system impact — and tells you exactly which combination gives you the best free protection available.
Important: Kaspersky antivirus is not included here. The US government banned the sale of Kaspersky software in June 2024 over national security concerns tied to its Russian origins. We only recommend software that’s trusted worldwide.
2026 AV-TEST Lab Results — Free Antivirus Rankings
AV-TEST is the most trusted independent antivirus testing lab. Here’s where the relevant free programs stand, on a 6/6 scale:
| Antivirus | AV-TEST Score | Performance Impact | Verdict |
|---|---|---|---|
| Windows Defender (Microsoft Defender Antivirus, Consumer) | 6/6 — Top Product | Minimal | Excellent |
| Avast Free Antivirus | 6/6 — Top Product | Low | Excellent |
| AVG AntiVirus Free | 6/6 — Top Product | Low | Excellent |
| Bitdefender* | 6/6 — Top Product | Very Low | Excellent |
| Avira* | 5.5–6/6 | Low | Very Good |
*A note on Bitdefender and Avira: AV-TEST’s published 6/6 scores are for Bitdefender Total Security and Avira Internet Security — the paid editions. Both companies confirm the free versions run on the same core detection engine, so the protection quality carries over in practice, but AV-TEST doesn’t separately lab-test the free editions under their own name. Worth knowing if you want to verify the exact claim yourself.
Source: AV-TEST Institute, home-user Windows evaluations, 2025–2026
Best Free Antivirus Combination
Windows Defender (real-time protection, 6/6 AV-TEST) + Malwarebytes Free (monthly scan) = the best free antivirus setup. Zero cost. Excellent protection. No conflicts.
10 Best Free Antivirus for PC
1. Windows Defender (Microsoft Defender Antivirus)
Best Free Antivirus — Already On Your PC
Windows Defender is built into every Windows 10 and 11 PC and earns a perfect 6/6 score in AV-TEST evaluations, classified as a Top Product. Microsoft has turned Defender into a genuinely excellent security tool most users never need to replace. It’s already installed, updates automatically, and uses minimal resources.
Key features: Built into Windows 10/11, no install needed · Perfect 6/6 AV-TEST protection score · Real-time malware and virus protection · Ransomware protection via Controlled Folder Access · Firewall and network protection included · No ads or upgrade prompts · Runs silently with negligible performance impact
Pros: Already installed, zero cost, perfect lab scores, no upsell pressure Cons: Lacks extras like a VPN or password manager Pricing: Completely free — built into Windows Best for: All Windows users — enable this first before anything else Rating: 9.5/10
2. Malwarebytes Free
Best Free Malware Scanner and Removal Tool
Malwarebytes is the best companion to Windows Defender. Defender handles real-time protection; Malwarebytes excels at finding and removing malware that’s already gotten in — particularly adware, spyware, and potentially unwanted programs that traditional antivirus tools miss.
Key features: Strong malware, spyware, and adware detection · Removes infections other antivirus programs miss · Browser Guard extension for safer browsing · Lightweight, minimal system impact · Free version fully functional for on-demand scanning
Pros: Best malware removal available, catches what Defender misses, lightweight Cons: Free version is scan-only, no real-time protection Pricing: Free | Premium starts around $44.99/year for one device (frequently discounted — check current pricing before buying) Best for: Pairing with Windows Defender for complete free protection Rating: 9/10
3. Bitdefender Antivirus Free Edition
Best Free Antivirus for Maximum Detection Rates
Bitdefender’s detection engine consistently scores 6/6 in AV-TEST evaluations of the paid Total Security product, and it’s rated among the best antivirus engines in the world. The free edition runs on the same core engine, is extremely lightweight, and needs virtually no configuration — the best pick if you want a set-and-forget third-party antivirus.
Key features: Built on a 6/6 AV-TEST-rated detection engine · Real-time malware and virus protection · Anti-phishing and anti-fraud protection · Very low CPU and RAM usage · Automatic updates · Zero-configuration interface
Pros: Excellent detection, lightest antivirus on this list, no setup required Cons: Very limited features — core protection only Pricing: Free | Total Security upgrade typically starts around $59.99/year on intro pricing (renewal rates run higher — confirm on Bitdefender’s site) Best for: Users wanting strong detection with near-zero system impact Rating: 9/10
4. Avast Free Antivirus
Best Free Antivirus with Extra Security Features
Avast Free Antivirus earns a perfect 6/6 AV-TEST score and packs the most comprehensive feature set of any free antivirus here — a Wi-Fi scanner, browser protection, gaming mode, and a ransomware shield, on top of core detection. With roughly 435 million users worldwide, it’s one of the most widely trusted free security tools.
Key features: Perfect 6/6 AV-TEST protection score · Real-time malware and virus protection · Wi-Fi network security scanner · Browser protection and anti-phishing · Gaming mode (pauses notifications) · Ransomware protection
Pros: Most feature-rich free option, perfect lab scores, Wi-Fi scanner Cons: Frequent upgrade prompts, heavier on resources than Bitdefender Pricing: Free | Premium Security intro pricing typically runs $39.99–$49.99/year for one device (renewal prices are notably higher — check before subscribing) Best for: Users wanting extra features beyond basic antivirus Rating: 8.5/10
5. AVG AntiVirus Free
Best Free Antivirus for Beginners
AVG shares its security engine with Avast (same parent company, Gen Digital) and also earns a perfect 6/6 AV-TEST score. The interface is cleaner and simpler — a clear dashboard, setup in under two minutes.
Key features: Perfect 6/6 AV-TEST protection score · Real-time malware and virus protection · Email shield for scanning attachments · Web shield blocking malicious sites · File shredder for secure deletion · Simple dashboard
Pros: Perfect lab scores, very easy to use, good for beginners Cons: Some advanced features locked behind the paid version Pricing: Free | Ultimate plan intro pricing is in a similar range to Avast’s, typically $39.99–$55.99/year — verify current rate on AVG’s site Best for: Beginners wanting simple, reliable, top-rated protection Rating: 8.5/10
6. Avira Free Security
Best Free All-in-One Security Suite
Avira Free Security goes beyond antivirus — built-in VPN (500MB/month), password manager, and system optimizer, all free. If you want a broad free security suite rather than just antivirus, Avira is the most complete option here.
Key features: Real-time malware protection · Built-in VPN, 500MB/month free · Password manager included · System performance optimizer · Automatic software updater · Browser safety extension
Pros: Most comprehensive free suite, VPN and password manager included Cons: VPN capped at 500MB/month on the free plan Pricing: Free | Avira Prime intro pricing typically starts around $59.99/year — confirm current rate before purchase Best for: Users wanting VPN and password manager bundled with antivirus, all free Rating: 8.5/10
7. Sophos Home Free
Best Free Antivirus for Families
Sophos Home Free runs on the same engine as Sophos’s enterprise business software, giving home users business-grade protection at no cost. It protects up to 3 devices from a single web dashboard — a solid fit for families.
Key features: Protects up to 3 devices (PC and Mac) · Web-based remote management dashboard · Parental content filtering · Ransomware protection · Business-grade security engine
Pros: Covers 3 devices, remote management, parental controls, enterprise-grade engine Cons: Advanced features limited in the free version Pricing: Free (3 devices) | Premium upgrade — check Sophos Home’s current pricing page, as published rates vary by region Best for: Families protecting multiple computers from one dashboard Rating: 8/10
8. Panda Free Antivirus
Best Free Antivirus for Old and Slow PCs
Panda Free Antivirus uses cloud-based scanning, meaning very little processing happens on your own machine. That makes it one of the lightest antivirus options available — well suited to older PCs that struggle with resource-heavy security software.
Key features: Cloud-based scanning, minimal local resource use · Automatic USB drive scanning · Rescue kit for severely infected PCs · Gaming mode · VPN included (150MB/day)
Pros: Extremely lightweight, USB protection, includes a VPN Cons: Detection rates trail Bitdefender or Windows Defender slightly Pricing: Free | Premium upgrade — check Panda’s current site for pricing, as it varies by promotion Best for: Older or low-spec PCs that can’t handle heavier security software Rating: 7.5/10
9. ZoneAlarm Free Antivirus + Firewall
Best Free Antivirus with Built-in Firewall
ZoneAlarm combines antivirus protection with a two-way firewall, giving dual-layer security at no cost. The firewall monitors both incoming and outgoing traffic for an extra layer beyond standard antivirus.
Key features: Antivirus and anti-spyware protection · Two-way firewall · Anti-phishing protection · 5GB free online backup · Identity protection alerts
Pros: Unusual antivirus-plus-firewall combo, includes online backup Cons: Can be resource-intensive, interface feels dated Pricing: Free | Pro plan — check ZoneAlarm’s current pricing page Best for: Users wanting combined antivirus and firewall in one free package Rating: 7.5/10
10. Comodo Free Antivirus
Best Free Antivirus with Sandbox Technology
Comodo includes a sandboxing feature that runs suspicious files in an isolated environment before they can touch your system — a proactive approach that catches new or unknown threats signature-based detection might miss.
Key features: Sandbox technology for unknown files · Real-time malware protection · Host intrusion prevention system · Secure DNS server · Rescue disk creation
Pros: Unique sandbox approach, proactive against unknown threats Cons: Complex interface, not ideal for beginners Pricing: Completely free Best for: Advanced users wanting proactive protection against unknown threats Rating: 7.5/10
Quick Comparison Table
| Antivirus | AV-TEST Score | Real-Time | Rating |
|---|---|---|---|
| Windows Defender | 6/6 Top Product | Yes | 9.5/10 |
| Malwarebytes Free | N/A — scanner | No, scan only | 9/10 |
| Bitdefender Free | 6/6 (engine-based)* | Yes | 9/10 |
| Avast Free | 6/6 Top Product | Yes | 8.5/10 |
| AVG Free | 6/6 Top Product | Yes | 8.5/10 |
| Avira Free | 5.5–6/6 (engine-based)* | Yes | 8.5/10 |
| Sophos Home Free | Not separately tested | Yes | 8/10 |
| Panda Free | Not separately tested | Yes | 7.5/10 |
| ZoneAlarm Free | Not separately tested | Yes | 7.5/10 |
| Comodo Free | Not separately tested | Yes | 7.5/10 |
*See the AV-TEST attribution note above — these scores reflect the paid edition’s tested engine, shared with the free version.
Antivirus Software to Avoid
Not all free antivirus software is safe. Steer clear of:
- Kaspersky — banned for sale in the US in 2024 over national security concerns
- Wolfram Antivirus — known scam that installs malware
- Total Antivirus 2020 — ineffective, relies on scare tactics
- Spybot Search and Destroy — outdated, weak detection rates in 2026
- Any antivirus from an unknown developer — always research before installing
Which Free Antivirus Should You Use?
- Already on Windows — enable Windows Defender immediately
- Best overall free protection: Windows Defender + Malwarebytes Free
- Highest detection with lowest system impact: Bitdefender Free
- Most features for free: Avira Free Security
- Easiest for beginners: AVG AntiVirus Free
- Protecting multiple family PCs: Sophos Home Free (3 devices)
- Old or slow PC: Panda Free Antivirus
- Want a firewall included: ZoneAlarm Free
Official Download Links
Always download antivirus software from official sites only:
Download Malwarebytes Free — Official Website
Download Bitdefender Free — Official Website
If your PC is already infected, removing the malware comes first, before relying on antivirus going forward. Our step-by-step guide covers the full free removal process: How to Remove a Virus from PC for Free
Once your PC is clean and protected, keeping your software organized is the next step. Our guide covers the essentials every computer should have: Essential Software Every Computer Should Have
Frequently Asked Questions
Is free antivirus enough for my PC in 2026?
Yes — for most users, free antivirus is completely sufficient. Windows Defender earns a perfect 6/6 AV-TEST score in 2026, the same rating as many paid programs. Avast Free and AVG Free also score 6/6, and Bitdefender’s free edition runs on the same engine that scores 6/6 in its paid form. The main advantage of paid antivirus is extra features like a VPN or identity protection — not better core protection.
What is the best free antivirus for Windows 11?
Windows Defender is already built into Windows 11 and earns a perfect 6/6 AV-TEST score. It’s the easiest choice — already installed, always updated. Add Malwarebytes Free for monthly scans for extra coverage. If you want a third-party option, Bitdefender Free Edition offers top-tier detection with minimal system impact.
Can I use two antivirus programs at the same time?
No — running two real-time antivirus programs causes conflicts and slows your PC down. The one exception is Malwarebytes Free, designed to run alongside other antivirus tools as an on-demand scanner. Windows Defender plus Malwarebytes Free is the recommended free combination.
Does free antivirus slow down my PC?
The best free options have minimal impact. Per 2026 AV-TEST results, Windows Defender and the Bitdefender engine show the lowest performance impact. Avast and AVG use slightly more resources. On older or slower PCs, Panda Free’s cloud-based scanning barely touches local performance.
Is Windows Defender good enough on its own?
Yes — Windows Defender earned a perfect 6/6 AV-TEST score in 2026, making it genuinely excellent. For most everyday users it provides complete protection on its own. Adding Malwarebytes Free for monthly scans covers any remaining gaps. This combination is what most security experts recommend for home users.
Why isn’t Kaspersky recommended?
The US government banned the sale of Kaspersky software in June 2024, citing national security concerns tied to its Russian origins. The UK and several EU countries have issued similar warnings. The software itself has tested effectively in independent labs historically, but the trust and security concerns make it an unsuitable recommendation here. Use Bitdefender, Avast, or Malwarebytes instead.
How often should I scan my PC for viruses?
With real-time antivirus enabled, your PC is continuously protected. Run a full manual scan with Malwarebytes Free once a month as an extra check, and scan immediately if you notice sudden slowdowns, unexpected pop-ups, browser redirects, or anything unusual.
What’s the best free antivirus for gaming PCs?
Bitdefender Free Edition is the best choice for gaming — minimal performance impact, runs silently without interrupting gameplay. Avast Free Antivirus also has a dedicated gaming mode that pauses notifications and reduces resource use during play.
Conclusion
Based on 2026 AV-TEST results, Windows Defender, Avast Free, and AVG Free earn a perfect 6/6 protection score directly under their own free-product name, and Bitdefender’s free edition shares the engine that scores 6/6 in its paid form. You don’t need to pay for solid antivirus protection.
The best free setup for most Windows users: enable Windows Defender, and run Malwarebytes Free for monthly scans. This zero-cost combination delivers excellent, independently verified protection.
- Best overall free setup: Windows Defender + Malwarebytes Free
- Best single free antivirus: Bitdefender Free Edition — strong engine, lightest footprint
- Most features for free: Avira Free Security — VPN and password manager included
- Best for families: Sophos Home Free — covers 3 devices
- Best for old PCs: Panda Free Antivirus — cloud-based, minimal local impact
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