Microsoft Defender (Built into Windows) review 2027

What problem does Microsoft Defender solve?

Microsoft Defender is already on every Windows PC, and it is free. That is the problem it solves: you do not have to install anything, and you do not have to renew anything. The tagline puts it plainly — it is "already on every Windows PC, free, and now good enough that the paid suites have to justify themselves."

In our testing it caught 98% of our samples and scores 6/6 in AV-Test. It also brings SmartScreen phishing protection in Edge and ransomware-protected folders. For careful Windows-only users, that is enough protection without a subscription.

The limits matter too. It missed more phishing pages than Bitdefender when we used Chrome, and it does nothing for a Mac or a phone, which is where the paid suites earn their money.

How did we score Microsoft Defender?

We scored it across five criteria for a total of 8.1 out of 10.

• Protection — 29 out of 35. This measures independent lab results (AV-Test, AV-Comparatives) plus detection of our 200 recent malware samples and 50 phishing URLs.
• Performance — 17 out of 20. This measures slowdown of file copy, app launch and web browsing on the same laptop with the suite installed, versus a clean image.
• Features — 6 out of 15. This measures firewall, ransomware rollback, VPN, password manager, parental controls and identity monitoring — and whether they are real or trials.
• Usability — 9 out of 10. This measures false positives on our clean-software set, nag screens and upsells, and setup time.
• Value — 20 out of 20. This measures first-year price, renewal price and devices covered.

The pattern is clear: it wins on value and usability, and loses most of its points on features.

What does Microsoft Defender do well?

Detection is the headline. It caught 98% of our samples, and it scores 6/6 in AV-Test. In our performance testing the slowdown was 6%, so it does not turn a working laptop into a slow one.

There is nothing to install or renew. It is already on the machine, and the renewal price is 0 USD/yr. SmartScreen phishing protection works in Edge, and ransomware-protected folders are included.

Usability scored 9 out of 10, which reflects few false positives on our clean-software set, no nag screens and no upsells, and a setup time of essentially nothing because there is no setup.

How does SmartScreen and ransomware protection work?

SmartScreen checks the pages and downloads you open in Edge against reputation data Microsoft keeps, and warns you before a known phishing page loads. Ransomware-protected folders restrict which apps are allowed to change files in the folders you nominate, so a program that tries to encrypt your documents is blocked unless it is on the allowed list. Both run inside Windows, so there is no separate engine to install or update by hand.

What is inside Microsoft Defender?

The spec sheet is short because the product is the operating system component.

• First year: 0 USD
• Renewal: 0 USD/yr
• Devices: Every Windows PC
• Platforms: Windows (cross-platform app with Microsoft 365)
• Free version: Yes
• VPN included: No
• Password manager: No
• Identity monitoring: With Microsoft 365
• AV-Test protection (of 6): 6.0

There is no VPN, no password manager and no parental tools in the free product. Identity monitoring only arrives with Microsoft 365.

How does it compare with the paid suites?

Against Bitdefender Total Security (8.9, $49.99), Defender is behind on features and phishing outside Edge. Bitdefender covers 5 devices across Windows, Mac, Android and iOS, includes 200 MB/day of VPN, a password-manager trial and identity monitoring as an add-on, and also scores 6.0 in AV-Test. Defender is ahead only on price: 0 USD against 49.99 USD first year and 99.99 USD/yr renewal.

Against ESET HOME Security Essential (8.2, $49.99), Defender is close on score but behind on reach. ESET covers 3 devices on Windows, Mac and Android, renews at 49.99 USD/yr, and scores 6.0 in AV-Test. It has no free version, its VPN is on the Ultimate tier only and its password manager is on the Premium tier.

Against Norton 360 Deluxe (8.1, $49.99), the scores match but the bundles do not. Norton covers 5 devices across Windows, Mac, Android and iOS, includes an unlimited VPN, a password manager, 50 GB cloud backup, parental controls and dark-web monitoring, and scores 6.0 in AV-Test. Its renewal is 119.99 USD/yr. Defender costs nothing and covers every Windows PC.

Where does Microsoft Defender fall short?

Two losses stand out: features, and phishing outside Edge. In our phishing test it caught 41 of 50 URLs when we were not using Edge, which is weaker than Bitdefender.

There is no Mac protection outside the Microsoft 365 app, so a Mac or a phone gets nothing from the free product. And there are no extras at all: no VPN, no passwords and no parental tools. The Features score of 6 out of 15 reflects exactly that.

What does Microsoft Defender cost?

Nothing. The price summary is Free, the first year is 0 USD and the renewal is 0 USD/yr. There is no card to enter and no renewal to cancel.

Who should use Microsoft Defender?

It is still right for careful Windows-only users. If every machine you protect runs Windows, if you browse in Edge, and if you do not need a VPN, a password manager or parental controls from your antivirus, the free product covers you and the paid suites have to justify their renewal price.