Numbers

Gemini and ChatGPT Both Hit 1 Billion Users

co-written by eustella AI12. August 2026, 09:56

Gemini greift nach ChatGPT. © Nano Banana 2 / Trending Topics

Within just under two weeks, Google and OpenAI have each reported that their AI assistants now reach more than one billion users. The way they announced it could hardly be more different – and the numbers are only partly comparable.

Google CEO Sundar Pichai made an event of it on August 11: in a post on X, he announced that the Gemini app had passed one billion monthly active users, calling it the fastest-growing product in the company’s history. Gemini is now the 14th Google product to cross the billion mark, joining Search, Gmail, Android, Maps, Chrome, Play and YouTube. Alongside the post, Josh Woodward, Vice President for Google Labs, Gemini and AI Studio, published a blog post with usage data.

OpenAI was considerably quieter about it. The company had already stated on July 31 that it had passed one billion active users and more than two million business customers – roughly three years and eight months after ChatGPT launched. In its most recent blog post, published August 6, which breaks down usage data country by country for the first time, the billion appears only as a subordinate clause: the statistics are meant to help people understand how more than one billion people are putting ChatGPT to work.

Gemini’s growth curve

What stands out on Google’s side is the pace of the past twelve months. In May 2025, Pichai still cited 400 million monthly active users for the Gemini app; by October 2025 it was 650 million, and around 750 million by February 2026. At I/O in June, Pichai spoke of 900 million, and the July quarterly report put the figure above 950 million. The final 50 million, in other words, were added within a matter of weeks.

On usage itself, Google reports that 63 percent of Gemini users speak to the assistant by voice, that more than 150 million images are generated daily, and that over 100 million active users are on iOS. Power users on macOS submit roughly twice as many prompts as users on other surfaces, according to the company. Announced for the coming weeks: support for more than 60 additional regional dialects, further app automations and new study tools.

An important caveat: the figure refers exclusively to the Gemini app. AI Mode in Google Search is counted separately and, on its own, also reaches more than one billion monthly active users.

Different ways of counting

A direct comparison of the two billion-user figures is tricky. Google explicitly refers to monthly active users of a single app. OpenAI, by contrast, applies its figure to all of the company’s AI interfaces – primarily ChatGPT, but also Codex and ChatGPT Work – and leaves open whether these are weekly or monthly actives. The last figure OpenAI officially confirmed was around 900 million weekly active users in February 2026. Analytics firms such as Sensor Tower place the ChatGPT app’s crossing of the billion mark in mid-2026.

Both companies are equally tight-lipped about money. Neither Google nor OpenAI discloses how many of these users pay. Google’s subscriptions start at $7.99 per month for Google AI Plus and run up to $100 for AI Ultra. In parallel, OpenAI is testing advertising in ChatGPT.

What the Similarweb data says about the race

A Similarweb report published on August 2, with data through May 2026, paints a more nuanced picture than raw user numbers do. The analysts propose three metrics – reach, retention and rate of growth – and conclude that no platform leads on all three.

Reach: ChatGPT records more web visits worldwide than Gemini, Claude and Perplexity combined. Gemini sits clearly in second place, with its curve bending noticeably upward since around September 2025 – timing that lines up with Google pushing Gemini and AI Mode deeper into Search. Claude moved within a narrow band for a long time before breaking upward from February 2026. Perplexity is the only one of the four platforms with a downward trend since its peak in October 2025.

Retention: Measured by stickiness – the share of monthly app users who return on a given day – ChatGPT leads. The more interesting comparison sits behind it: Claude narrowly beats Gemini on this metric despite a user base many times smaller. A larger share of Google’s audience, in other words, uses the app only occasionally.

Rate: Here the ranking inverts. In a year-over-year comparison of worldwide monthly active app users, Claude grows fastest in percentage terms, followed by Perplexity and Gemini. ChatGPT grows slowest in percentage terms – but adds the most in absolute numbers thanks to its much larger base.

A similar pattern shows up in advertising spend: ChatGPT invests the most in paid search in absolute terms, Gemini follows, and Claude spends the least while scaling its spending fastest.

On usage patterns, Similarweb corrects a widespread assumption: programming and developer topics account for a considerably larger share of activity on both Claude and Gemini than on ChatGPT. ChatGPT’s category profile most closely resembles that of a general search engine replacement.