ChatGPT Is Still Huge, But Rival AI Chatbots Are Catching Up Fast

For three years, ChatGPT had the rarest advantage in tech: Its name was the category. Nobody said they were using generative AI. They said they were “using ChatGPT,” the way people once said they’d Google something.

But it’s possible ChatGPT’s glory days from 2023 are over.

ChatGPT’s share of the AI assistant market dropped below 50% for the first time in March 2026, then closed May at 46%, according to Sensor Tower’s new State of AI 2026 report. Google Gemini holds 28%. Claude has climbed to 10%.

None of that means ChatGPT is dying. The app crossed 1 billion monthly users in May, becoming the fastest app in history to hit that mark, ahead of TikTok, YouTube, and Instagram. OpenAI is now pushing ChatGPT toward a superapp bundling shopping and agents, timed to an IPO process it has already begun.

What’s ending is the monopoly on being the only AI app anyone’s normie cousin has heard of. Decrypt reported in May that ChatGPT’s web traffic share had already slid from 77.6% to 53.7% in a year. Sensor Tower’s numbers just confirm it crossed into minority territory.

The more alternatives in the market, the more brand-agnostic consumers are getting.

Gemini’s rise is mostly a distribution story, and the count depends on who’s doing it. Google told investors Gemini hit 750 million monthly users in February, then announced more than 900 million at its developer conference in May. Sensor Tower’s outside tracking, which measures only Gemini’s own app and site, puts that same month at 662 million.

Either number lands in the same place. ChatGPT’s dominance is fading not because it’s worse, but because distribution and defaults now matter more than raw capability—Gemini’s integration across Android, Search, Chrome, and Workspace gives it an advantage that benchmarks can’t capture.

Claude’s U.S. share nearly tripled, from 5% in December to 14% in May, and that spike has a name attached. In late February, Anthropic refused Pentagon demands to drop safeguards against mass surveillance and autonomous weapons, and the Department of Defense, renamed the Department of War, branded the company a supply chain risk. OpenAI signed its own deal with the same department days later.

ChatGPT uninstalls in the U.S. spiked roughly 200% above average the week of March 9, Sensor Tower found. Claude out-downloaded ChatGPT for five straight days that March, before ChatGPT’s lead snapped back. Brand trust turned out to be a feature too.

Crypto traders picked a favorite, and it’s not close

Buried in the user-persona data is the report’s best detail. Grok users are about four times more likely than the general population to be crypto traders, the widest skew of any assistant Sensor Tower measured.

For some reason, ChatGPT is ‘meh’ among degens. Claude is a distant second, ahead of Copilot, with ChatGPT users barely above the population baseline.

Grok’s edge traces back to X, where it ships free inside Premium and reads live posts the second a meme coin starts trending, an advantage no standalone chatbot has.

So the structural factors really reinforce each other here—Grok’s embedded in X’s ecosystem where crypto traders already congregate, it taps directly into real-time sentiment and meme coin chatter, Musk’s personal crypto enthusiasm shapes the platform’s culture, and the user base itself skews toward people already steeped in crypto Twitter dynamics. This creates a self-reinforcing loop that naturally pulls Grok toward crypto-focused output.

It also offers a similar experience to ChatGPT depending on the situation-a chat box, artifacts, coding capabilities, generative image, generative video which ChatGPT doesn’t offer, web searching, connectors, etc.

Claude’s runner-up spot tracks with last fall’s Alpha Arena contest, where Grok and Claude Sonnet posted real-money trading gains on the Hyperliquid exchange while GPT-5 and Gemini 2.5 Pro each lost more than a quarter of their stake. Crypto Twitter remembers who made it money, so they may not be too crazy judging by their chatbot preferences.

The revenue numbers back up the user numbers. Claude’s average revenue per U.S. mobile user jumped from under $0.50 last September to $2.76 in May, ahead of ChatGPT’s $1.74, and 13% of Claude’s users now pay for a subscription, the highest conversion rate in the report. OpenAI is heading toward an IPO with the biggest audience in AI history and a shrinking claim on what that audience actually prefers.