ChatGPT’s market share falls below 50% for first time

ChatGPT Falls Below 50% Market Share for First Time as Rivals Gain Ground

OpenAI’s ChatGPT has lost its majority hold on the AI assistant market for the first time, with its “True Audience” share dropping below 50% in March 2026, according to Sensor Tower’s State of AI 2026 report released on Monday. The milestone marks a turning point for the chatbot that launched the generative AI era, even as it reached 1 billion monthly active users faster than any app in history.morningstar

A Shrinking Lead

Sensor Tower’s report, which measures unique users across both mobile apps and web, found that ChatGPT’s share fell to 46.4% by the end of May, down from above 50% in January. Google’s Gemini now commands 27.7% of the market with 662 million monthly users, while Anthropic’s Claude holds 10.3% with 245 million users. Claude’s True Audience share in the U.S. has more than tripled, driven largely by strong web traffic.techcrunch

The broader market, however, remains highly concentrated. ChatGPT, DeepSeek, and Gemini together account for nearly 90% of total time spent on AI assistant apps in the first quarter of 2026. Other competitors including Grok, Perplexity, and Meta AI each hold less than 5%.morningstar

Growth Amid Competition

The decline in market share does not reflect a shrinking user base for ChatGPT. The app became the fastest ever to reach 1 billion monthly active users in May 2026, achieving the milestone in just three years — faster than TikTok, YouTube, or Instagram. OpenAI has reported 900 million weekly active users and 50 million paying subscribers, with annualized revenue reaching $25 billion.prnewswire

In the first half of 2026, consumers are on pace to download 2.3 billion AI apps and spend over $4.2 billion on them, according to Sensor Tower estimates. The pie is growing rapidly, but ChatGPT is capturing a smaller slice of it.techcrunch

IPO Pressure

The shifting competitive dynamics come at a critical moment for OpenAI. The company confidentially filed for an IPO on June 8, with Goldman Sachs and Morgan Stanley serving as lead underwriters. The Wall Street Journal reported in January that OpenAI is targeting a public listing in the fourth quarter of 2026, with valuations discussed at up to $1 trillion. Anthropic is also preparing a late-2026 listing, adding pressure on both companies to demonstrate durable market leadership.cmcmarkets