Claude's app users jumped 1,260% in a year, but ChatGPT is still far bigger

Claude, the AI assistant from Anthropic, is the fastest-growing AI app right now. Its monthly app users rose 1,260 percent in the third quarter of 2026 compared with a year earlier. But ChatGPT is still far bigger, with 1.4 billion monthly users. The figures are estimates from the market research firm Sensor Tower.

What the numbers show

Sensor Tower compared seven AI assistants. Over the same year, ChatGPT grew 70 percent and Google's Gemini grew 166 percent. Gemini has 591 million monthly users. Claude holds a share of about 4 percent. Meta AI grew 675 percent, the biggest jump after Claude. Perplexity was the only app in the group that shrank.

Sensor Tower says Claude's surge began in the United States in March. It points to OpenAI's partnership with the U.S. Department of War and a Super Bowl ad campaign as triggers. Anthropic had run spots poking fun at advertising in ChatGPT.

Why app counts miss people

Many Claude users never open the app. Between April and October, 73 percent of Claude users used only the website and 17 percent used only the app. ChatGPT is the reverse: 56 percent use only the app, 26 percent only the web and 18 percent both.

Sensor Tower also says nearly half of Claude's U.S. app users used LinkedIn in the past six months. That suggests many use Claude for work. Anthropic also earns most of its money from businesses and developers, and that usage barely shows up in app statistics.

The ad money behind the growth

AI companies are spending heavily to get downloads. U.S. ad spending by the assistants rose 429 percent in the third quarter. Claude made up 15 percent of it. ChatGPT has made up 54 percent so far this year.

• About 22 percent of all downloads this year came from paid ads.
• For Meta's Muse agent, 62 percent of downloads were paid.
• For Meta AI, the figure is 52 percent.
• Downloads across the group fell 11 percent in the third quarter.

What the data cannot tell you

Claude grew from a low starting point, so the gap to ChatGPT and Gemini is still wide. Its users spend 39 minutes a week in the app, below the group average of 43. The figures are Sensor Tower's own projections, not numbers from the companies.

Anthropic has filed its prospectus for an I.P.O., which means selling shares to the public. Sensor Tower says its user estimates track Anthropic's quarterly revenue closely, so investors may watch this kind of data.

What to do

The biggest or most advertised assistant is not automatically the best one for your work. Since so much of the growth is driven by ads, try two or three assistants on a real task before committing. Check both the app and the website.