A billion people use ChatGPT. That's an unprecedented number

In May 2026, ChatGPT reached one billion monthly active users — approximately three years after its launch. According to Sensor Tower data cited by CNBC, this is the fastest user base growth in technology history. In this regard, ChatGPT surpassed TikTok, Instagram, YouTube, and Google Maps — all platforms we previously considered absolute champions of viral growth.

Year-on-year, ChatGPT grew by 62 percent, which would be an amazing result for any other application. But for ChatGPT, it looks modest — especially compared to its main competitor.

Claude grows by 640 percent annually. And that's a different league

Anthropic, the company behind the Claude chatbot, recorded approximately 56 million monthly active users in the second quarter of 2026. Compared to ChatGPT, this is a fraction. But the year-on-year growth rate reaches an incredible 640 percent.

What does this mean in practice? While ChatGPT gained approximately 380 million new users in a year, Claude grew more than ten times faster in relative terms. And according to Sensor Tower survey data, users who installed Claude in the first quarter of 2026 spent five percent less time in ChatGPT than in the previous eight months. It's not crushing the competition — but it's the first measurable proof that Claude is indeed taking a bite out of OpenAI's pie.

For the Czech market, the good news is that Claude is available in Czech — although its natural strength remains English texts and coding. The basic version of Claude is free, premium Claude Pro costs 20 USD per month (approximately 460 CZK), which is a comparable price to ChatGPT Plus.

Two very different strategies

Comparing ChatGPT and Claude is not just about numbers — it's about two fundamentally different philosophies of what AI should be.

OpenAI bet on the mass market. ChatGPT is everywhere: in mobile apps, integrated into Windows 11, available via API for millions of developers. The strategy is simple: maximum reach, lowest barrier to entry.

Anthropic chose a different path. Claude is primarily a tool for professionals, businesses, and developers. It focuses on security, reliability, and the ability to process long documents. While ChatGPT has more users, Anthropic apparently generates more money per user — and that is a key difference from the perspective of future profitability.

Anthropic heads for IPO: valuation over 965 billion dollars

On June 1, 2026, Anthropic confidentially filed a draft S-1 registration statement with the U.S. Securities and Exchange Commission (SEC). It is thus the first major AI lab to formally begin the process of going public. The initial public offering (IPO) could take place as early as autumn 2026 — likely on the NYSE or Nasdaq.

Just four days before filing the S-1, Anthropic closed a Series H funding round of 65 billion dollars at a valuation of 965 billion dollars — making it the world's most highly valued private AI company, just ahead of OpenAI. Morgan Stanley, Goldman Sachs, and JPMorgan Chase were selected as the lead underwriters for the IPO.

Anthropic's annual run-rate revenue, according to VentureBeat, reached approximately 47 billion dollars by the end of May 2026 — an increase from approximately 9–10 billion at the end of 2025. This represents an approximately fivefold jump in just six months. OpenAI's IPO is reportedly planned for "the coming weeks," according to Reuters sources.

Why revenue matters more than user count

Traditionally, tech companies are valued by user count. But the AI era brings different rules. Claude is significantly stronger in the enterprise segment — companies pay for API access, Teams plans, and specialized integrations. OpenAI shares these customers, but Anthropic is building a reputation as a more reliable, safer partner in this segment.

An example is the collaboration with Amazon Web Services — Claude is deeply integrated into the Amazon Bedrock platform, which opens doors to thousands of corporate customers who cannot afford to experiment with less proven tools.

Simply put: ChatGPT may have more people using it to write emails and recipes. But Claude has clients who pay hundreds of thousands of dollars for it annually.

What this means for the average user in the Czech Republic

The competition between ChatGPT and Claude is only good news for end-users. Both platforms have significantly improved their Czech language capabilities in recent months. Claude 3.7 Sonnet and the newly announced Claude 4 handle Czech at a solid level — although native speakers may still occasionally encounter imperfections in text naturalness.

ChatGPT-4o and GPT-5 are generally somewhat more natural in Czech due to a longer development cycle for multiple languages. However, for demanding analytical work and processing long documents, many professionals prefer Claude — even in a Czech-speaking environment.

Both platforms offer a free basic version available from the Czech Republic without restrictions. Premium plans start from 20 USD per month.

A race that's just beginning

A billion ChatGPT users is a monumental number — but it doesn't guarantee future dominance on its own. The history of technology is full of stories of products that were first yet ultimately lost (think MySpace or Internet Explorer). What will be decisive in the AI era?

Security and reliability for businesses. Speed of model innovation. Ability to integrate into workflows. And it is in these areas that Anthropic is building a strong position — even though it significantly lags behind OpenAI in absolute user numbers.

Both upcoming IPOs — Anthropic and OpenAI — will be historic moments for the entire tech industry. For investors and analysts, it will be the first opportunity to peek under the hood of the finances of the world's two most influential AI companies. And it might provide an answer to the question that interests the market most: who actually earns more?