ChatGPT in 2026: An AI Giant Facing Fierce Competition

ChatGPT: A Rapid Rise but Threatened

Last May, ChatGPT made history by becoming the mobile application to reach one billion active users faster than any other. This achievement surpassed giants like Google Maps and Google Chrome. However, this success comes with increasingly intense competition. According to the "State of AI" report by Sensor Tower, a data analytics company, ChatGPT now faces heightened competition three years after its launch. This recent document also ranks the most downloaded AI applications in France and worldwide.

A Declining Dominance

Sensor Tower's data reveals that in March 2026, ChatGPT saw its market share fall below 50% for the first time. By May, this share had decreased to 46%, while Google Gemini and Claude captured 28% and 10% of the market, respectively. The remaining 16% is divided among Grok, DeepSeek, Perplexity, Meta AI, and Microsoft Copilot. Over the past three years, ChatGPT has been gradually losing ground.

Several factors explain this rebalancing. Google Gemini, for instance, has managed to leverage its vast Android user base and integration into the Mountain View ecosystem to gain traction. Meanwhile, Claude, developed by Anthropic, has experienced rapid growth, particularly in the United States, thanks to its performance in programming and in-depth research. Its market share in the U.S. rose from 5% in December 2025 to nearly 14% in May 2026.

The Impact of a Controversial Agreement

A major event accelerated these changes: in February 2026, OpenAI signed an agreement with the Pentagon to deploy advanced AI systems in classified environments. This agreement was poorly received by users, leading to a 200% increase in ChatGPT uninstalls compared to the usual average during the week of March 9 to 15, according to Sensor Tower. Many users then turned to Claude, which had declined a similar agreement. Between March 1 and 5, Claude recorded more daily downloads than ChatGPT.

The Challenges of Retention

In March 2026, OpenAI faced a challenging period. Although the company remains a leader in retention, ChatGPT's churn rate slightly increased, rising from 12.7% in January to 14.5% in April. This increase coincides with the introduction of ads in ChatGPT and the fallout from the agreement with the Pentagon, as noted by Sensor Tower. Meanwhile, Claude is seeing its churn rate decrease rapidly.

The Landscape of Generative AI Applications in 2026

Despite these challenges, OpenAI maintains a notable lead over its competitors. ChatGPT remains at the top of downloads, even as the market stabilizes and becomes more closed. According to Sensor Tower, in the first quarter of 2026, only 15% of new applications made it into the global top 50 AI assistants and companions, down from more than two-thirds two years earlier. However, ChatGPT has lost its top position in certain markets like Mexico, Taiwan, and Argentina. Globally, Google Gemini ranks second, followed by Dola.

Here are the ten most downloaded generative AI applications worldwide in the first half of 2026:

• ChatGPT
• Google Gemini
• Dola AI
• Grok
• Claude
• Doubao
• Meta AI
• Seekee
• Qwen Chat
• AI Chatbot – Nova

In France, the ranking is similar, except for some popular applications in Asia like Dola AI, Doubao, or Seekee. ChatGPT is in the lead, followed by Google Gemini, with Grok completing the podium. Notably, NotebookLM and Mistral Vibe, formerly known as Le Chat, are in ninth position.

Here are the ten most downloaded generative AI applications in France in the first half of 2026:

• ChatGPT
• Google Gemini
• Grok
• Claude
• Meta AI
• Perplexity
• Google NotebookLM
• Suno
• Mistral Vibe
• Donna