Topline
ChatGPT became the fastest app to reach 1 billion monthly active users and remained the market share leader, but rivals like Anthropic’s Claude and Google’s Gemini have been closing the gap and even beating OpenAI’s app on metrics such as monetization, according to a new report.
Key Facts
ChatGPT’s iOS and Android apps hit 1 billion monthly active users last month, according to Sensor Tower’s State of AI report—just three years after arriving on smartphone app stores.
While ChatGPT continued to lead in monthly users, the report showed its market share fell below 50% for the first time in March this year, down from 81% in March 2024.
Anthropic’s Claude has seen a significant jump in users since the start of 2026 and is beating its rivals in monetization, with 13% of its iOS users paying for a subscription compared to ChatGPT’s 8%.
The Claude app also makes 1.5 times as much per user as ChatGPT, with an average revenue of $2.76 per user compared to $1.74 for OpenAI’s app.
While ChatGPT remains the biggest AI app by monthly users in most countries except Russia and China, Google’s Gemini is the fastest growing in key markets like the U.S., Canada, most of the European Union, Japan and South Korea.
OpenAI’s app, however, remains the best at retaining new users who sign up each month, with a user retention rate of 86% last month—though Claude’s is now closing the gap, having risen to 73.7%.
Did ChatGPT’s Pentagon deal spark a loss of users?
ChatGPT has a definite early-mover advantage, as the report notes: “users remain willing to try alternative AI assistants.” This became most evident in March this year as OpenAI’s decision to sign an agreement with the Pentagon—after Anthropic’s blacklisting—triggered a surge in uninstalls of the ChatGPT app, likely in protest. ChatGPT uninstalls peaked at 202% above its usual numbers in the second week of March, the report shows. The Claude app was the biggest beneficiary of this uninstall spree, as its global market share rose from 5.1% in February to 10% in April.
Tangent
The Wall Street Journal reported last week that OpenAI was considering major price cuts for its AI tools in a bid to compete with rival Anthropic. While this is directed at enterprise customers and won’t directly affect app spending, it comes at as the monetization of AI platforms and the cost of using agents is facing growing scrutiny. On the consumer apps front, Google slashed the subscription price of its cheapest Gemini AI Plus plan from $8 per month to $5 per month earlier this month. OpenAI’s cheapest “Go” tier pricing remains at $8 per month. Claude, on the other hand, does not offer a “lite” or low-cost tier for users as its base plans start at $20 per month. ChatGPT, Gemini and Claude’s monetization efforts are likely to face some pressure as Apple begins to roll out Siri AI later this year, which has features that partly run locally on a user’s iPhone or other Apple devices instead of relying on a subscription.
Big Number
$4.25 billion. That is how much consumers are expected to spend on AI apps in the first half of 2026, according to the Sensor Tower report. This is up from $1.83 billion in H1 2025 and $3.1 billion in H2 2025.