Windows · Security & Antivirus
Avast Free Antivirus for Windows
Free real-time antivirus from Avast that replaces Microsoft Defender's real-time engine and upsells frequently toward paid Avast One and Premium Security tiers.
Updated August 9, 2026 · Reviewed by SoftNexi Editorial Team, Software research and documentation
Overview
Avast Free Antivirus is a genuinely free, always-on real-time scanner — unlike Malwarebytes' free tier, it is a full replacement for Defender's real-time protection rather than an on-demand supplement. Installing it switches Windows Security's active antivirus provider from Defender to Avast automatically.
The free tier includes core malware scanning, a basic firewall component (behavior varies by version and platform), and web/email protection modules. Avast pairs this with frequent, sometimes aggressive prompts to upgrade to Avast One or Premium Security, which add VPN, a stronger firewall, ransomware shields on arbitrary folders, and other extras. Expect these upsell interstitials as a normal part of the free experience, not a bug.
Avast's corporate history includes a widely reported data-collection controversy (the Jumpshot browsing-data business, discontinued in 2020) that led to regulatory scrutiny. Anyone privacy-sensitive should read Avast's current privacy policy and data-handling disclosures before installing it, rather than relying on outdated assumptions in either direction.
Avast and AVG are both owned by Gen Digital and share the same underlying detection engine; the two free products are close siblings with different branding and default UI rather than fundamentally different technology.
Key features
- Free real-time antivirus scanning that replaces Defender's real-time engine
- Web and email protection modules
- File shredder and basic PC-cleanup utilities
- Wi-Fi network inspector for finding local vulnerabilities
- Frequent in-app upsell prompts toward Avast One / Premium Security
- Shares its core engine with AVG AntiVirus Free
System requirements
- Operating system
- Windows 11 and Windows 10 (64-bit)
- Account
- An Avast account is used for registration and cloud features
- Internet connection
- Required for activation and definition updates
How to install Avast Free Antivirus
1. Download from the vendor
Use avast.com/free-antivirus-download rather than a third-party portal.
2. Review each setup screen
Uncheck optional browser add-ons or extra tools you don't want before continuing.
3. Let it take over real-time protection
Windows Security will list Avast as the active provider once setup finishes.
4. Decline or accept the trial
A premium trial is often offered; free protection continues either way.
How to use it
1. Run a full scan after install
Establish a clean baseline before relying on real-time protection alone.
2. Review installed add-ons periodically
Remove any browser components you did not intend to keep.
3. Check for silent upgrade prompts
Distinguish genuine security alerts from marketing dialogs for paid tiers.
Safety and privacy
- Download only from avast.com; free antivirus brand names are heavily impersonated by malicious download sites.
- During setup, review each screen carefully — optional add-ons and upgrade offers are presented as default-selected in places.
- Bundled software
- The official installer's core antivirus is not bundled with unrelated third-party software, but it actively promotes Avast's own paid products and browser tools during and after setup.
- Privacy
- Avast's past data-collection practices (the discontinued Jumpshot business) drew regulatory attention. Review Avast's current privacy policy and in-app data-sharing settings if this concerns you.
Known risks
- Upgrade prompts and cross-promotion can be persistent and easy to click through without noticing.
- As with any free security product monetized through upsells, review installed browser extensions and optional components afterward.
What's new
Current release
Avast updates its engine and definitions continuously through auto-update. Check the developer's release notes for version-specific detail.
Pros and cons
Pros
- Genuinely free real-time protection
- Regularly updated detection engine
- Extra utilities like Wi-Fi inspector included free
- Widely used, well-known product
Cons
- Frequent upsell prompts in the free tier
- History of data-practice controversy worth reviewing
- Setup screens require careful reading to avoid unwanted extras
- Shares engine with AVG, so little differentiation between the two
Verdict
Avast Free Antivirus is a capable, genuinely free real-time alternative to Microsoft Defender, but go through setup carefully and expect ongoing upgrade prompts. Privacy-sensitive users should read the current policy before installing.
Frequently asked questions
Does Avast Free Antivirus support Windows 11?
Yes, it supports current 64-bit releases of Windows 11 and Windows 10.
Where should I download Avast Free Antivirus?
Download it from avast.com/free-antivirus-download rather than a third-party portal, since free antivirus brand names are heavily impersonated by malicious download sites.
Is Avast Free Antivirus really free?
Yes, its real-time scanning, web/email protection, and basic firewall components are genuinely free. Avast frequently prompts you to upgrade to paid Avast One or Premium Security tiers for extras like a VPN and stronger firewall.
Can it run alongside Microsoft Defender?
No. Installing Avast switches Windows Security's active antivirus provider from Defender to Avast, and running two real-time engines together is not supported.
What doesn't the free tier cover?
The free tier doesn't include the VPN, ransomware shields on arbitrary folders, or stronger firewall found in Avast's paid Avast One and Premium Security tiers.