| Feature | | Windows Defender | Avast Free | | :--- | :--- | :--- | :--- | | Cloud Console | No (Pro only) | No | Yes (limited) | | RAM Usage | ~15MB | ~150MB | ~80MB | | Zero-day detection | AI Behavioral | Signature-based | Cloud lookup | | Data selling | No | N/A | Yes (historically) | | Mac/Linux support | Yes | No (Mac has limited) | Yes |