Guess what's the most visited site on the web. No it's not Google or Facebook.

TikTok Was the Internet’s Most Visited Site in 2021, Even Beating Google

New research shows video-sharing app first topped the charts in February and has generally stayed No. 1 since August, according to Cloudflare

By Joseph Pisani, WSJ

Updated Dec. 22, 2021 3:18 pm ET

TikTok really was everywhere this year.

The app, known for its silly dancing videos, was the world’s most visited site on the internet in 2021, surpassing last year’s leader, Alphabet Inc. GOOG 0.84% ’s Google, according to Cloudflare Inc., NET -0.55% a cloud-infrastructure company that tracks internet traffic.

The app, owned by Beijing-based ByteDance Ltd., has had a rapid rise, hooking people with its secretive algorithm, which delivers video clips that it thinks you would like. It has turned dancing influencers Addison Rae and Charli D’Amelio into household names, getting cast in TV shows, commercials and movies.

Earlier this year, TikTok said it had more than one billion monthly users.

Like other social-media sites, TikTok has its dark side. The video-sharing app’s algorithms can drive minors to videos about sex, drugs and eating disorders, investigations by The Wall Street Journal have found.

TikTok didn’t immediately respond to a request for comment Wednesday.

Cloudflare said TikTok first started topping the charts as the world’s most visited site in February. But it grew in popularity in August, where it generally maintained the top spot for the rest of the year.

To come up with its rankings, Cloudflare said it uses data it has on global internet traffic patterns, including app usage or when a person visits a site on a web browser.

A Wall Street Journal investigation found that TikTok only needs one important piece of information to figure out what you want: the amount of time you linger over a piece of content. Every second you hesitate or rewatch, the app is tracking you. Photo illustration: Laura Kammermann/The Wall Street Journal

TikTok was ranked seventh last year, but Cloudflare said 2020’s list captured the last four months of the year because it started tracking web traffic in September 2020.

Google, which includes its search function, maps, language translation and other services, ranked second this year. It was followed by Meta Platforms Inc. ’s Facebook, Microsoft Corp. , Apple Inc. , Amazon.com Inc. , Netflix Inc. , Alphabet’s YouTube, Twitter Inc. and Meta’s WhatsApp, according to Cloudflare.

Meta’s social-media app Instagram fell off 2021’s list, and was replaced by its messaging app WhatsApp, according to Cloudflare.

Write to Joseph Pisani at joseph.pisani@wsj.com