The share of ChatGPT in web traffic is gradually declining, while competitors continue to gain audience. All this is happening just as businesses are increasingly looking beyond OpenAI.
For a long time, the word ChatGPT was almost synonymous with artificial intelligence. But now it is becoming harder to defend that association.
According to SimilarWeb, in May 2025, ChatGPT controlled 77.6% of global web traffic among generative AI services. By April 2026, this share had dropped to 53.7%. OpenAI is still the market leader, but over the year the company lost about a quarter of its share.
And most importantly, this traffic did not go to any single competitor.
Google Gemini grew over the same period from 7.27% to 26.7%, nearly quadrupling its market share. Claude rose from 1.37% to 7.95%, showing almost sixfold growth.
Grok, Perplexity and DeepSeek also continued to grow, though not as sharply. The AI market is starting to fragment among different players, and it is OpenAI that now feels the consequences of this fragmentation the most.
ChatGPT’s share is falling while Gemini and Claude continue to grow. Source: SimilarWeb.
But it is important to understand what exactly the web traffic data shows. It accounts for visits to chatbot websites, not API requests, corporate contracts, or use of models inside third-party applications. If a person goes to ChatGPT.com to write a letter, it counts. But a developer running millions of requests through API Claude is not reflected in these statistics at all.
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Therefore, such data is more likely to show the popularity of services among regular users than actual revenue or the scale of technology adoption.
And here comes a second set of data, which shows a similar picture.
This week, the Ramp AI Index, which tracks paid AI subscriptions at more than 50,000 US companies, published an update for May 2026. And for the first time ever, the service recorded that more companies are paying for Anthropic solutions than for OpenAI products.
In April, the share of businesses using Anthropic grew by 3.8% and reached 34.4%. For OpenAI the situation is the opposite: its share fell by 2.9% to 32.3%.
Anthropic has overtaken OpenAI by number of paying companies in the US. Source: Ramp AI Index.
Ramp Chief Economist Ara Kharazyan called this a stunning turnaround. Just a year ago, only 9% of companies on the platform paid for Anthropic products. Now this figure has quadrupled. For OpenAI over the same 12 months, corporate adoption grew by only 0.3%.
The main driver of Anthropic‘s growth has been Claude Code, a tool for programming with AI agents that is quickly gaining popularity among developers at companies of any scale.
Uber CTO publicly said that the company spent its entire AI budget for 2026 in just four months, largely due to the use of Claude Code. According to him, monthly API expenses for a single engineer reached $500–2000.
But there is an important nuance to the Ramp data. OpenAI said through its representative that the company’s largest corporate deals do not go through corporate cards at all.
“We are engaged in large-scale business transformation. Such contracts are not paid by credit card,” the company told Axios.
And that makes sense. The Ramp methodology covers most corporate AI spending, but still does not fully reflect the market.
At the same time, Ramp believes that it will not be easy for Anthropic to maintain its leadership. The report highlights several risks.
First, the token-based payment model pushes users to switch to more expensive models. Second, in recent weeks Claude has faced outages and complaints about quality. And cheaper inference platforms are growing rapidly in the market, as seen in Ramp‘s own data.
The report separately notes that Codex from OpenAI performs similar tasks for developers at a lower cost, and switching between services is now quite easy.
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Traders and investors are closely watching this battle. As previously reported by Decrypt, Anthropic shares on the secondary market Forge Global were valued at about $1 trillion, higher than $880 billion for OpenAI on the same platform. And just three months ago, Anthropic was valued at only $380 billion.
In fact, the market is showing that it is starting to believe in the company’s current growth, even if some expectations still look overly optimistic.
Both OpenAI and Anthropic have criticized such valuations. But even so, this data still serves as a kind of thermometer for market sentiment, albeit on relatively illiquid platforms.
Meanwhile, Gemini from Google has continued to strengthen its position at least since mid-2025. Much of this is helped by integration into Android, an advantage in distribution that competitors simply do not have.
ChatGPT grew largely due to the novelty effect and being the first major player on the market. But both of these advantages are gradually losing strength.
Now the main question for OpenAI is different: can the company regain its leadership through its products alone? According to Ramp, next month the market will be watching especially closely the growth of Codex and new corporate contracts for OpenAI.
