Do you still need a separate antivirus in 2025?
Windows Defender vs paid AV suites – threat models, performance and value.
Quick verdict
- Good enough – Windows Defender blocks > 99 % of real-world malware in AV-Test 07/2025.
- Upgrade if … you need identity-theft insurance, cross-platform licences or built-in VPN.
- Skip it if you already sandbox downloads, patch fast and avoid shady cracks.
Threat model first
Ask “what am I protecting and from whom?” If the answer is “bank logins against run-of-the-mill phishing”, Defender + browser warnings handle it. If you run a small business or family fleet, paid AV centralises dashboards and adds rollback for ransomware.
Lab scores 2025 (summary)
| Suite | Malware block rate | False positives | CPU impact* |
|---|---|---|---|
| Windows Defender (built-in) | 99.4 % | 0 | Baseline |
| McAfee AV Plus 2025 | 99.7 % | 1 | +1.8 % |
| Avast Premium 2025 | 99.6 % | 0 | +2.1 % |
* AV-Comparatives Performance Test, May 2025, Core i5-12500 / 16 GB / NVMe.
FAQ
Is Windows Defender enough for everyday users?
For most home users on Windows 11, Defender combined with SmartScreen and browser isolation is sufficient. Paid AV adds extras such as VPN, dark-web monitoring and multi-device licences.
Will extra antivirus slow down my PC?
Modern suites run light, but Defender still wins most performance benches. Independent AV-Comparatives 2025 tests show <2 % CPU overhead for both McAfee and Avast.