Free Antivirus That's Actually Good
Antivirus marketing is loud and full of half-truths. Here's what you actually need (often less than you think) and what to avoid.
Short answer
On Windows 10/11: use the built-in Microsoft Defender. It's free, already running, and as good as most paid options. Add Malwarebytes free for occasional second-opinion scans.
Best free antivirus on Windows
Microsoft Defender (already installed)
If you have Windows 10 or 11, Defender is built in. It runs all the time, updates automatically, and scores in the top tier in independent tests (AV-TEST, AV-Comparatives).
- Already on your PC. Nothing to install
- Doesn't slow you down
- No popups, no upsells
- Integrated with Windows security features
Check it's on: Start > Settings > Privacy & Security > Windows Security > Virus & threat protection. Should say "No action needed."
Malwarebytes Free
Run on-demand scans. Best for if you think you may have already gotten infected. Not always-on protection.
- Excellent at removing PUPs (potentially unwanted programs) and adware
- The free version is on-demand only (no real-time)
- Use it like a flashlight: scan when suspicious, otherwise let it sit
Best free antivirus on Mac
macOS has built-in protections:
- XProtect: scans new files against known malware signatures
- Gatekeeper: blocks apps not signed by trusted developers
- System Integrity Protection: blocks tampering with system files
For most Mac users, that's enough. Add Malwarebytes for Mac if you want occasional manual scans.
What to avoid
Norton, McAfee, Avast, AVG
These come pre-installed on many new PCs as trial software. Reasons to uninstall:
- Slow down your computer significantly
- Constant upsell popups
- Subscriptions auto-renew at high rates
- Protection isn't measurably better than Defender
To uninstall: Settings > Apps > Installed Apps > find Norton/McAfee/etc > Uninstall.
"AntiVirus Total Protect Suite Pro 2026" and similar names
If you see a popup telling you your computer is infected and offering antivirus, that popup IS the scam. Real antivirus doesn't sell itself through popups.
"Free" antivirus from unknown sites
Only download antivirus directly from the company's official website. Search "Malwarebytes" on Google, click the official site (malwarebytes.com), download from there. Don't download from "softfreedownload.com" or similar.
When you might want paid antivirus
- Running a small business with multiple devices and want central management
- Family with kids who download a lot of random stuff
- You handle sensitive financial or medical data
- Specific industry compliance requirements
If you do want paid: Bitdefender Total Security or Kaspersky (for non-government users) are the top picks. Both around $40-60/year per machine.
The real security upgrades (not antivirus)
What actually keeps you safer than fancy antivirus:
- Strong unique passwords via a password manager
- 2-factor authentication on important accounts
- Keep software updated (Windows, browser, apps)
- Don't click links in emails or texts unless you're certain
- Backup your files so ransomware can't hold you hostage
If you think you're already infected
- Disconnect from internet (turn off Wi-Fi, unplug Ethernet)
- Run a full scan with Microsoft Defender
- Download and run Malwarebytes free
- Remove anything they find
- Change important passwords from a clean device
- Consider a Windows reset if uncertain
Phone antivirus?
iPhone: doesn't need antivirus. Apple's app sandbox prevents most malware.
Android: built-in Google Play Protect is fine if you only install from Play Store. If you sideload apps from random sites, that's where infections come from.
Worried your computer might be infected?
Isaac can scan and clean it up. Usually a one-time service, not an ongoing subscription.