ChatGPT Market Share Falls Below 50% in 2026

ChatGPT market share dropped below 50% in 2026

AI assistant market share at the end of May 2026

ChatGPT is still first, 18.7 points ahead of Gemini. The three largest assistants hold 84.4% between them, and every other service shares the remaining 15.6%.

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46.4%ChatGPT

27.7%Gemini

10.3%Claude

15.6%All others

ChatGPT has held less than half of the AI assistant market since spring 2026. The figures come from State of AI 2026, a report by the app analytics firm Sensor Tower. It tracked the drop in two steps, first in March and then at the end of May.

ChatGPT's unique-user share dipped under half in March

Sensor Tower measures share with a figure it calls True Audience share. It counts the people who use each assistant across mobile apps and the web, and it counts a person only once even if they use both. On that measure, ChatGPT fell below 50% for the first time in March 2026.

The report says the drop came as Gemini and Claude gained users in several large markets at once. ChatGPT did not lose its lead.

By late May, ChatGPT held 46.4% of the AI chatbot market

By the end of May 2026 ChatGPT's share stood at 46.4%, with Gemini at 27.7% and Claude at 10.3%. Those three assistants add up to 84.4%, which leaves 15.6% for every other service combined.

ChatGPT's lead over the next assistant is still 18.7 points. The market remains concentrated in a few services, but it is no longer one service's market.

More than 1.1 billion people still use ChatGPT every month

Minutes per user per month in each AI assistant

Sensor Tower's engagement figures. ChatGPT users spend nearly twice as long in the app as Claude users, and more than twice as long as Gemini users.

min0100200

215 minChatGPT

120 minClaude

100 minGemini

Monthly active users (MAU), the number of people who open an app at least once in a month, are a separate measure from share. ChatGPT has more than 1.1 billion of them, more than any other AI assistant.

ChatGPT hit one billion monthly users faster than TikTok

In May 2026, ChatGPT became the fastest mobile app ever to pass one billion monthly users. Sensor Tower says it got there in three years, ahead of TikTok, YouTube and Instagram.

TechCrunch attributes the fall in share to the rise of Gemini and Claude. For the model and plans behind it, see GPT-5 in ChatGPT: Pricing, Free Tier, Models.

Users spend about 215 minutes a month in ChatGPT

The average ChatGPT user spends about 215 minutes a month in the app. Claude users spend about 120 minutes, up 40, and Gemini users about 100, up 14.

In the first quarter of 2026, ChatGPT, Gemini and DeepSeek together took nearly 90% of all time spent in AI assistant apps. Gemini and Claude gained usage time quickly, though ChatGPT still leads.

Gemini market share and Claude's user base grew fastest

Monthly active users of the three largest AI assistants (May 2026)

ChatGPT has about 1.7 times as many users as Gemini and about 4.5 times as many as Claude.

B00.51

1.1BChatGPT

662MGemini

245MClaude

The share ChatGPT gave up went mostly to two services, Google's Gemini and Anthropic's Claude. Gemini is the larger of the two. Claude is the one growing faster.

Gemini holds 27.7% of the market with 662 million users

Gemini is a clear second, with 27.7% of the market and 662 million monthly users. That puts it at about three-fifths of ChatGPT's user count.

Sensor Tower says Gemini gained most in Europe, the US, Japan and South Korea. For the latest model, see Gemini 3.5 Pro is still not in the Gemini API.

Claude users rose 452% in a year, and its US share neared 14%

Claude is smaller, at 10.3% and 245 million monthly users, but Sensor Tower calls it the fastest-growing challenger of 2026. In May its unique user count was up 452% on a year earlier.

In the US, its share rose from 4.4% to nearly 14% over the same period, and the report links that growth to Claude catching on with professional users and people who come looking for a specific task. The service itself is covered in What Is Claude AI? Free Plan, Models, vs ChatGPT.

Why ChatGPT market share declined as rivals caught up

Sensor Tower names two main drivers: Gemini's reach through Google's own products and Claude's uptake among professional users. Many US users who uninstalled ChatGPT in March appear to have switched to Claude.

Android and Google services carried Gemini into new markets

Gemini is tightly integrated into Android, and Google also offers it across its other services. That puts it in front of people who never went looking for a separate AI app.

Sensor Tower describes the market as moving from a single dominant player toward several strong ones. TechCrunch reports that the same study found users increasingly willing to switch between assistants.

Uninstalls spiked after OpenAI's Department of War deal

In the US, ChatGPT uninstalls rose sharply after OpenAI signed an agreement with the Department of War. In the week of March 9–15 they peaked at about 200% above the app's average.

Many of those users seem to have moved to Claude, whose maker had declined a partnership with the Pentagon. That dispute is covered in Anthropic Pentagon rulings split; Claude dropped.

From March 1 to 5, Claude had more daily downloads than ChatGPT. ChatGPT has led every day since, but by a much smaller margin than before March.

The AI market race is now about paying users and ad reach

Sensor Tower expects AI apps to reach close to 2.3 billion downloads and more than $4.2 billion in user spending worldwide in the first half of 2026. Downloads and spending are still rising, but more slowly than before. So the industry is shifting from pure user growth toward monetization.

Claude turns 13% of its users into paid subscribers

A paid conversion rate is the share of users who pay for a subscription. Claude's is 13%, the highest in the industry according to Sensor Tower. Claude has the smallest user base of the three, but a larger share of its users pay.

ChatGPT's ad impressions grew over 7x from March to May

ChatGPT started testing ads in February 2026. By May, about 17% of its daily users had been shown one, mostly for software and shopping. Sensor Tower says ad impressions grew more than sevenfold between March and May.

Sensor Tower sees AI assistants becoming a new place to find products and ads, alongside search and social media. Early advertisers are mostly in shopping, software, travel and financial services.