ChatGPT is used by about 1.2 billion people every week, the Gemini app passed 1 billion monthly users in August, and Claude has gone from a niche tool to roughly one in ten visits to AI chatbot websites. A year ago ChatGPT had more than three quarters of that traffic; in September 2026 it had 56%. Here is who uses which AI assistant in 2026, measured as carefully as the public data allows, and what it means for companies in Croatia and the DACH region.
The short answer: a two-and-a-half horse race
The consumer AI assistant market in 2026 has two mass-market leaders, ChatGPT and Google Gemini, each with roughly a billion users, and one fast-growing challenger, Anthropic's Claude, which is much smaller by users but grew the fastest over the past year. Meta AI reaches about a billion people too, mostly inside WhatsApp, Instagram and Messenger. Everyone else, including DeepSeek, Grok, Perplexity, Microsoft Copilot and Mistral's assistant, shares the rest.
| Assistant | Latest user figure | Metric and source | Web visit share, Sep 2026 |
|---|---|---|---|
| ChatGPT (OpenAI) | ~1.2 billion | Weekly users, OpenAI DevDay, 29 Sep 2026 | 56.4% |
| Gemini (Google) | 1 billion+ | Monthly users of the Gemini app, Sundar Pichai, 11 Aug 2026 | 25.0% |
| Meta AI | ~1 billion | Monthly users across Meta's apps, Meta, May 2025 | not tracked as a website |
| Claude (Anthropic) | ~245 million (estimate) | Monthly users, Sensor Tower model, May 2026; Anthropic does not disclose | 9.6% |
| Mistral Vibe (ex Le Chat) | not disclosed | No public user figure | below 1% (not listed) |
| Manus | not disclosed | Agent product, no public user figure | not listed |
ChatGPT: still the default, but no longer alone
ChatGPT's growth has not stopped. OpenAI reported 400 million weekly users in February 2025, 800 million at DevDay 2025 in October, 900 million in February 2026 and about 1.2 billion at DevDay 2026 on 29 September. At DevDay OpenAI also turned ChatGPT into a platform for always-on agents and third-party apps, which makes that audience a distribution channel for other software.
What has changed is its share. According to Similarweb's monthly tracker, ChatGPT had 77.5% of all visits to gen-AI chatbot websites in July 2025 and 52.7% in June 2026, its low point so far. Since then it has edged back up to 56.4% in September. In the app market Sensor Tower measured an even lower figure: 46.4% at the end of May 2026, the first time ChatGPT ended a month below half of the AI-assistant app audience since its launch in November 2022.
Gemini: Google's distribution advantage pays off
Gemini is the biggest winner of the past 18 months. The Gemini app had about 350 million monthly users in March 2025 and 400 million at Google I/O in May 2025. It passed 750 million in early 2026, 900 million at I/O 2026 and 1 billion in August 2026, the 14th Google product to reach that mark. Its share of chatbot web visits went from 9.4% in July 2025 to a peak near 28% in May and June 2026, then eased to 25.0% in September.
The reason is distribution. Gemini is built into Android, Chrome, Gmail and Google Workspace, and Google's AI Mode in Search reaches over a billion people on its own. For many users Gemini is simply the AI assistant that is already there. Note that the 1 billion figure counts only the standalone Gemini app, not AI features inside Search or Workspace.
Claude: small by users, fastest by growth, highest value per user
Claude is the story of 2026. Its share of chatbot web visits was 1.9% in July 2025 and 2.3% in October 2025. By May 2026 it was 9.2%, and in September 9.6%, roughly a fourfold increase in a year. In the United States the share is higher: Similarweb measured 13.4% in May 2026.
The turning point came in late February 2026. After the US Department of Defense designated Anthropic a supply-chain risk, Claude climbed to No. 1 among free iPhone apps in the US on 28 February, ahead of ChatGPT, for the first time. In March an Anthropic spokesperson told TechCrunch that Claude's paid subscriptions had more than doubled since the start of the year. Anthropic credited its Super Bowl campaign and new product launches as well. Sensor Tower's model estimates Claude's monthly audience grew from about 60 million in December 2025 to about 245 million in May 2026; Anthropic itself does not publish a number.
Claude's users are also unusually valuable. Much of its use is work: coding with Claude Code, documents, spreadsheets and research. That matches the company's revenue picture: as we showed in our analysis of AI lab revenue and valuations, Anthropic's run rate reached about $65 billion in July 2026, mostly from business customers and the API rather than consumer subscriptions.
Meta AI, DeepSeek, Grok and the long tail
Meta said in May 2025 that Meta AI had passed 1 billion monthly users across Facebook, Instagram, WhatsApp and Messenger. That figure includes many people who received an AI answer inside an app they were already using, so it is not comparable with people who open ChatGPT or Claude on purpose. Similarweb does not count Meta AI as a chatbot website.
Among the websites, the long tail is small. In Similarweb's May 2026 data DeepSeek had 4.1%, Grok 2.4%, and Perplexity and Microsoft Copilot 1.3% each. Copilot's real reach is larger, because most of its use happens inside Windows and Microsoft 365, which web-traffic data does not capture.
Mistral and Manus: different games
Mistral renamed its assistant from Le Chat to Mistral Vibe on 28 May 2026 and repositioned it from a chatbot to a platform for chat, work automation and coding. Mistral does not publish user numbers. The last public milestone was one million downloads in about two weeks after the mobile launch in February 2025, when it topped the French App Store. Its web share is too small to appear in Similarweb's top list. Mistral competes on European data residency, open weights and enterprise deployments, not on consumer reach, and with €3 billion of fresh capital raised in September it can afford to.
Manus is an autonomous agent rather than a chat assistant, so chatbot market-share data does not capture it. After Meta's acquisition was unwound, Manus resumed operating independently on 1 September 2026 and raised more than $500 million in October. It does not disclose user numbers either.
Europe, Croatia and the DACH region: use is high, use at work is not
Eurostat's 2025 survey gives the only official data on who actually uses these tools in Europe. 32.7% of people aged 16 to 74 in the EU used generative AI tools in the three months before the survey. Austria (39.4%) is above the average, Germany (32.3%) is at the average, and Croatia (27.5%) is below it. Denmark leads with 48.4%.
The more important number is use at work. Only 9.0% of Croatians used generative AI for work in 2025, against 15.4% in the EU, 15.8% in Germany and 21.2% in Austria. At the same time 13.4% of Croatians used it for formal education, well above the EU's 9.3%. Students are bringing AI habits into the labour market faster than employers are adopting the tools.
What this means for companies in Croatia and the DACH region
- Your employees already use these tools. With over a billion weekly ChatGPT users and a quarter of Croatians using generative AI privately, the question is not whether staff use AI but whether they use it with company data on private accounts. A sanctioned tool and a clear policy are cheaper than an incident. See our guide to shadow AI governance.
- Do not choose your platform by consumer popularity. The most used assistant is not automatically the best fit for your data, workflows and compliance needs. Claude has about a tenth of the consumer web traffic, yet Anthropic, earning mostly from business customers, reached a $65 billion revenue run rate. Use a structured AI vendor selection scorecard instead.
- Close the work-use gap with training. Croatia's 9% work use is less than half of Austria's. Companies that train staff now gain a productivity lead over competitors. Start with an AI literacy programme, which the EU AI Act also requires.
- Be visible in all three big assistants. Customers increasingly ask ChatGPT, Gemini and Claude instead of searching. With a market this fragmented, optimising only for ChatGPT leaves out more than 40% of the audience. Our guide to generative engine optimisation (GEO) shows how.
- Plan for more than one model. Shares moved by more than 20 points in a year. A multi-model setup lets you follow the best model without rebuilding your processes.
The bottom line
In 2026 AI assistants became mass-market products: ChatGPT reaches about 1.2 billion people a week, Gemini over a billion a month, and a third of Europeans use generative AI. ChatGPT's dominance has given way to a market with two giants and a fast-growing third player in Claude. For companies in Croatia and the DACH region the takeaway is practical: the tools are already in your employees' pockets, use at work still lags, and the companies that close that gap in a controlled way will benefit most.
Frequently asked questions
How many people use ChatGPT in 2026?
OpenAI said at DevDay on 29 September 2026 that ChatGPT has about 1.2 billion weekly users, up from 800 million in October 2025 and 900 million in February 2026. OpenAI reports weekly users only and does not publish monthly or daily active users.
What is ChatGPT's market share in 2026?
By Similarweb's count of visits to gen-AI chatbot websites, ChatGPT had 56.4% in September 2026, down from 77.5% in July 2025. Gemini had 25.0% and Claude 9.6%. Sensor Tower, which measures app and web audiences, put ChatGPT at 46.4% at the end of May 2026. Statcounter, using a different method, reports a much higher ChatGPT share.
How many users does Claude have?
Anthropic does not publish a consumer user count. Sensor Tower estimates about 245 million monthly users in May 2026, up from about 60 million in December 2025. Claude's share of chatbot web visits rose from 2.3% in October 2025 to 9.6% in September 2026, and Anthropic said its paid subscriptions more than doubled in early 2026.
How many people use Google Gemini?
Sundar Pichai announced on 11 August 2026 that the Gemini app had passed 1 billion monthly active users, up from 750 million in early 2026 and 400 million in May 2025. The figure covers only the standalone Gemini app, not AI features in Google Search or Workspace.
How many people in Croatia use generative AI?
According to Eurostat, 27.5% of people aged 16 to 74 in Croatia used generative AI tools in 2025, below the EU average of 32.7%. Only 9.0% used them for work (EU: 15.4%), while 13.4% used them for formal education (EU: 9.3%). In Germany 32.3% and in Austria 39.4% used generative AI.
Want your team to use AI safely and productively?
We help companies in Croatia and the DACH region choose between Claude, ChatGPT, Gemini and Mistral, roll out a sanctioned AI assistant with clear policies, and train employees to use it well. As a Claude Certified Architect based in Zagreb, we start with your processes, not the hype.
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