Documents from Meta, the company that owns Facebook and Instagram, show that its leaders, including CEO Mark Zuckerberg, thought TikTok was doing better than Meta in areas where Meta expected to be strong.

The document from February 2022 has talks between some Meta leaders about what Facebook and Instagram plan to do and where they stand in the market. In one message, Zuckerberg said Facebook was a "challenger" that had "lost its popularity and speed." He also said that TikTok makes a "feeling of shared context" where friends see the same popular internet content.

Mosseri agreed that Facebook is now trying to catch up, saying it's not the main place people find things anymore. He suggested that YouTube might be the best place to find things now, but he thought TikTok would become even bigger than YouTube eventually, based on the information Meta had.

The best way for Facebook to be different is to be the main place where people find new things. But it's interesting that [TikTok] is only videos and is doing much better than us," Mosseri wrote. "I think they are making the social media market bigger and also taking users from TV, long videos, and Netflix.

Mosseri was right. One study found that in 2021, people in the U.S. watched TikTok for more time on average than YouTube. Another study in 2023 showed that young people aged 4 to 18 spent much more time on TikTok than on YouTube. Last year, TikTok began allowing videos up to 60 minutes long to compete with YouTube.

This week, Netflix added a new feature to its phone app that is similar to TikTok. It shows short videos in a vertical feed, suggesting films and shows the user might like based on their personal taste.

In the trial, the U.S. government is trying to show that Meta broke competition laws by buying companies like Instagram and WhatsApp to control social media. This document could hurt their case because, inside the company, Meta leaders were talking about how TikTok was doing much better than Facebook.

For example, Zuckerberg said that even though Facebook still had the most daily or weekly users, people were spending less time on it compared to other apps.

He also mentioned that TikTok helps people feel connected because they often see similar things in their feeds, especially if they share interests with their friends.

"This makes it social because you can assume your friend has seen the content, instead of sending it to them," the CEO said. "It would be great if we could do this with different topics and content on Facebook."

Other executives also contributed their perspectives.

Will Cathcart, who is in charge of WhatsApp, said that when TikTok users comment on videos about a specific topic, the app will slowly show them and others who comment the same videos.

Stan Chudnovsky, who was a Vice President and General Manager at Meta, said that Meta was now competing in a market that had become very divided, with "many companies slowing down our growth."

He said that just adding a new feature, like they did with Stories, isn't enough now because people have many other apps to use, like TikTok, Twitter, and YouTube.

John Hegeman, who was in charge of advertising and is now in charge of making money, agreed that TikTok was clearly better at things like short videos, how they rank videos, and tools for making videos. But he thought Meta could catch up if creators also put their videos on Reels.

However, he wasn't sure how far behind Meta was with its machine learning, technology, and tools for making things. The document shows that Meta thinks Facebook is not as strong as its competitors in the social media market.

Other papers appearing in the trial also showed Meta was worried about competition. Zuckerberg said last month that TikTok's success was a risk to Meta and had made its growth slower.