Compare software

Avira Free Security vs Microsoft Defender: catalog facts
Avira Free Security	Microsoft Defender
Freemium Free tier with paid Internet Security and Prime plans.	Paid Included with a paid Microsoft 365 subscription, with a free trial available.
Windows, macOS, Android, iOS	Windows, macOS, Android, iOS
Real-time antivirus at no cost Extra tools like software updater and browser safety	Manages security for several family members and devices from one dashboard Dark web monitoring for more than 60 types of personal information
Closed source Upsells paid plans and premium tools	Requires a Microsoft account and a Microsoft 365 subscription Closed source, with protection tied to Microsoft's cloud services
Downloadable app	Downloadable app
Closed source	Closed source
License not stated	License not stated
Not stated if an account is needed	Account needed
Needs internet	Not stated if it works offline
Official website Full listing and sources Checked September 24, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.