Third-Party Data Suggests ChatGPT Share Fell Below 50% as Gemini and Claude Grow

Third-party app analytics suggest ChatGPT’s AI assistant share has slipped below 50%, while Gemini and Claude continue gaining users.

Third-party app analytics suggest ChatGPT's share of AI assistant usage has fallen below 50% for the first time. According to Sensor Tower figures cited by TechCrunch, OpenAI's chatbot commanded 46.4% of the market by the end of May, down from above 50% earlier in the year.

That should be read as an outside estimate, not an official OpenAI metric. Still, it is useful directional data: AI assistant usage is no longer a one-product market.

This isn't a collapse — ChatGPT still has over 1.1 billion monthly active users, and it became the fastest app ever to reach that milestone earlier this month. But it's a clear signal that the AI assistant landscape is fragmenting fast as users explore alternatives.

Who's Gaining

The two biggest beneficiaries are Google's Gemini and Anthropic's Claude.

Gemini now holds 27.7% of the market, with 662 million monthly active users. Its growth is largely driven by deep integration across Google's ecosystem — Chrome, Android, Google Workspace, and search. When millions of people open a new Android phone or Chromebook, Gemini is right there, ready to go. That distribution advantage is hard to beat.

Claude has climbed to 10.3% of the market with 245 million monthly active users. While smaller in raw numbers, Claude has the highest paid conversion rate in the industry: 13% of Anthropic's users pay for a subscription. That's a strong signal of willingness to pay for quality, especially among knowledge workers and developers. Claude has built a reputation for productivity use cases and is closing in on ChatGPT's user-retention rate.

The remaining market — below 5% each — includes Grok, Perplexity, DeepSeek, Meta AI, and others. None have broken out as a clear fourth player yet, but the combined "other" category is growing.

Users Are Switching

Sensor Tower's data shows that users are increasingly willing to switch between assistants. This matters for both product strategy and retention:

• OpenAI's DoD deal triggered a 295% spike in ChatGPT uninstalls in February, suggesting values alignment matters to users, not just features

• Claude is gaining ground on productivity and coding use cases, where its accuracy reputation is strongest

• Gemini benefits from convenience — it's pre-installed and frictionless for Google users

The switching behavior suggests no one has won the "default AI assistant" slot on users' devices yet, despite ChatGPT's head start.

The Numbers Behind the Shift

The exact totals vary by measurement method, so treat these as third-party estimates rather than audited company figures.

Sensor Tower estimates that people will download nearly 2.3 billion AI apps in the first half of 2026, spending over $4.2 billion — more than double the $1.83 billion in H1 2025. However, both download and spend growth rates have decelerated, signaling market maturation.

Hours spent on AI apps are projected to jump from 17.2 billion hours in H1 2025 to roughly 36 billion hours in H1 2026. The top three assistants (ChatGPT, Gemini, Claude) command 89% of that time.

Regionally, Asia recorded its first-ever download decline of 3.3% in Q1 2026, driven by drops in China and India. Despite leading globally in total downloads, Asia still trails North America and Europe in in-app spending — a split worth watching for companies deciding where to invest in premium features.

OpenAI's Monetization Pivot

With growth decelerating, OpenAI is pivoting toward monetization beyond subscriptions. ChatGPT started showing ads in February 2026, and by May, an average of 17% of daily users were seeing them. The biggest advertiser categories so far are software, shopping, media and entertainment, and food and dining.

ChatGPT's shopping integrations are already driving real referral traffic to retailers like Target, Walmart, and Costco. Amazon, which blocked ChatGPT's web crawlers, has seen stagnant referral traffic as a result.

Meanwhile, Walmart's Spark AI assistant has been gaining ground compared to Amazon's Rufus, which has seen flat user growth. Sensor Tower noted that Amazon shoppers who used Rufus spent more time in the app and converted at higher rates — so on-platform AI assistants are influencing purchasing behavior when users actually engage with them.

What This Means

The erosion of ChatGPT's market share is normal for a maturing market. Competitors are building genuinely good alternatives, and users are acting rationally by trying them. But it also means OpenAI can no longer coast on first-mover advantage — it needs to defend its position through product improvements, monetization strategy, and continued investment in the quality that made ChatGPT dominant in the first place.

The real battle going forward isn't just about which model is smarter — it's about distribution, monetization, and trust. And on those fronts, the game is wide open.

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