For the First Time, ChatGPT Reportedly Has Less Than Half of the AI Assistant Market

OpenAI's ChatGPT lost its majority share of the AI assistant market for the first time, dropping to 46.4% as of May 31, according to Sensor Tower data. The decline follows OpenAI's controversial Pentagon deal, a shift toward enterprise focus, and the introduction of ads, while competitors like Anthropic's Claude and Google's Gemini gained ground.

OpenAI reportedly no longer dominates the AI assistant market. A report from Sensor Tower reported on by TechCrunch https://techcrunch.com/2026/06/16/chatgpts-market-share-slips-below-50-for-first-time/ says that although OpenAI’s ChatGPT is still the number one-ranked AI assistant product, it can now brag only the plurality, not the majority of users. ChatGPT’s grip on AI assistant market share was much stronger at the start of this year, when it reportedly had more than 50%, but as of May 31, it was down to an all-time low of 46.4%, TechCrunch notes. Around 2023, ChatGPT looked on track to become a “genericized trademark”—a term for when a trademarked name becomes the accepted term for a whole product category. But anecdotally, I don’t hear people say things like “ just ChatGPT it https://artofwriting.berkeley.edu/writing/just-chatgpt-it/ ” anymore. In March, OpenAI made a deal with the Pentagon https://www.npr.org/2026/02/27/nx-s1-5729118/trump-anthropic-pentagon-openai-ai-weapons-ban at a time when its chief competitor, Anthropic, was noisily feuding with the Pentagon https://gizmodo.com/pentagon-reportedly-hopping-mad-at-anthropic-for-not-blindly-supporting-everything-military-does-2000722286 over that company’s stance against autonomous killer robots and AI mass surveillance. Anthropic managed to become a sort of folk hero https://fortune.com/2026/05/16/ftc-anthropic-pentagon-ai-regulation-federal-trade-commission/ , even if that reputation was probably somewhat unearned https://gizmodo.com/the-pentagons-claude-use-in-iran-is-a-reminder-that-anthropic-never-objected-to-military-use-2000728150 . Some AI users revolted in the wake of OpenAI’s deal, which CEO Sam Altman acknowledged https://x.com/sama/status/2028640354912923739 looked “opportunistic and sloppy.” An anti-OpenAI organization called QuitGPT https://quitgpt.org/ what , which calls itself a “grassroots campaign by the people, for the people,” formed. Its website claims that “ChatGPT took Trump’s killer robot deal. It’s time to Quit.” That site says 4 million people have joined its boycott. And at the same time, OpenAI more broadly was in the midst of a wrenching and sudden shift in its self-image, from freewheeling and fun to…whatever it is now. Anthropic’s surge in revenue-generating enterprise customers had triggered a “ code red https://www.wsj.com/tech/ai/openais-altman-declares-code-red-to-improve-chatgpt-as-google-threatens-ai-lead-7faf5ea6 ” in late 2025. By mid-March of 2026, OpenAI was reportedly changing its internal strategy to focus on enterprise and productivity https://gizmodo.com/openai-reportedly-pivoting-to-a-focus-on-business-and-productivity-only-2000734341 . About a week after that report, OpenAI killed its video-generating app, Sora https://gizmodo.com/r-i-p-sora-2024-2026-2000737664 . Oh, and ChatGPT also started showing ads https://openai.com/index/testing-ads-in-chatgpt/ earlier this year. When an Anthropic Super Bowl commercial made fun of OpenAI for its ads, Sam Altman responded by getting embarrassingly testy in public https://www.bbc.com/news/articles/ce3edyx74jko . In short, ChatGPT’s loss of dominance arrived during a less-than-ideal year for its brand image—although in the “plus” column, OpenAI won its legal war with Elon Musk, https://finance.yahoo.com/news/openai-prevails-in-musks-lawsuit-paving-the-way-for-ipo-175338618.html so its year hasn’t been completely without high points. The market share of Anthropic’s Claude, according to this report, is 10.3%—nowhere near Gemini’s 27.7%, let alone ChatGPT’s 46.4%. However, earlier analysis of the Sensor Tower report from Reuters https://www.reuters.com/technology/chatgpt-app-hits-1-billion-monthly-active-users-record-time-data-shows-2026-06-02/ says that Claude’s pace of year over year monthly active user growth absolutely blew OpenAI’s away, with 640% for Claude, and only 62% for ChatGPT. If you’re wondering how Grok, the AI assistant whose parent company is SpaceX, measures up in the Sensor Tower report, the answer is not very well. It’s essentially lumped into the “other” section, alongside Perplexity, MetaAI, and DeepSeek, which collectively boast 5% of AI assistant market share.