News of TikTok's achievement was reported by tech-security company Cloudflare. The social media app made quite the climb this year, considering that in 2020 it was ranked No. 7 while Google sat at the top. Some experts attribute TikTok's success to the pandemic as people look for more ways to occupy their time. The app claimed 1 billion monthly active users in September. After TikTok, the top domains this year were as follows: 2. Google.com 3. Facebook.com 4. Microsoft.com 5. Apple.com. 6. Amazon.com 7. Netflix.com 8. YouTube.com 9. Twitter.com 10. WhatsApp.com.