ChatGPT Traffic Falls as Anthropic, Google Gain Share

SimilarWeb data show ChatGPT’s share of global generative AI website traffic declined from 77.6% in May 2025 to 53.7% in April 2026. Anthropic surpassed OpenAI in a separate commercial gauge, and Google’s Gemini accounted for 26.7% of chatbot site visits in April 2026.

The SimilarWeb measure counts visits to chatbot websites rather than API calls or embedded usage inside other apps. ChatGPT remains the single largest destination for chatbot visits but lost about 24 percentage points over 12 months. Gemini rose from 7.27% to 26.7% in the same period, and Anthropic’s Claude climbed from 1.37% to 7.95%. Other platforms, including Grok, Perplexity and DeepSeek, also registered increases.

The Ramp AI Index, which tracks paid AI subscriptions across more than 50,000 U.S. businesses, reported that Anthropic’s presence on the index increased to 34.4% of companies tracked in April, up 3.8 percentage points. OpenAI’s share on Ramp fell to 32.3%, down 2.9 points. Ramp’s lead economist, Ara Kharazian, described the change as “a stunning reversal.”

Ramp’s report points to Claude Code, Anthropic’s coding tool, as a main driver of its enterprise adoption. An executive at a large technology firm reported that the company exhausted its 2026 AI budget within four months and attributed the rapid consumption largely to Claude Code, citing per-engineer monthly API costs in a range between $500 and $2,000.

OpenAI highlighted limits of Ramp’s methodology, noting the index captures corporate card payments and does not reflect large enterprise contracts. An OpenAI spokesperson stated the company is “driving enterprise transformation at scale” and that major enterprise deals typically are not processed via credit card.

On secondary trading platforms, implied valuations for Anthropic have been near $1 trillion, above OpenAI’s approximate $880 billion valuation on the same venues. Anthropic’s secondary-market valuation was about $380 billion three months earlier. Secondary pricing reflects trades on limited-liquidity platforms and can change rapidly.

Ramp identified several risks that could affect Anthropic’s business lead, including a token-based pricing model that may push users to costlier models, recent service outages and quality complaints, and growth of lower-cost inference platforms. Ramp also noted that OpenAI’s developer tools perform similar tasks at lower apparent cost, which could reduce switching friction for some teams.

Google’s Gemini has expanded distribution in part through integration with Android devices, increasing exposure to a large user base. Industry participants say key metrics to watch in coming months include enterprise contract renewals, API and inference usage, and adoption of developer-focused tools such as Codex and Claude Code; those figures will indicate whether current trends in web traffic and paid subscriptions persist.