For the first three years after its launch, ChatGPT was the undisputed king of AI assistants. That grip is now loosening. According to TechCrunch, citing Sensor Tower’s State of AI Report for 2026, ChatGPT’s global market share has fallen below 50% for the first time, sliding to 46.4% by the end of May 2026. Google’s Gemini and Anthropic’s Claude are picking up the slack.
This does not mean ChatGPT is struggling in absolute terms. It recently became the fastest app ever to hit 1 billion monthly users, and it still leads the field with over 1.1 billion monthly users. But the gap between it and its closest competitors is shrinking, and user behavior is shifting in ways that matter for the entire industry.
The numbers tell a clear story about where AI assistants stand heading into the second half of 2026. ChatGPT is still dominant, but the market around it has matured enough that users feel comfortable switching, comparing, and paying for alternatives.
The current breakdown of monthly active users across the major AI assistants looks like this:
- ChatGPT: 1.1 billion monthly users, 46.4% market share
- Gemini: 662 million monthly users, 27.7% market share
- Claude: 245 million monthly users, 10.3% market share
- Grok, Perplexity, DeepSeek, and Meta AI: each below 5%
ChatGPT held over 50% market share until January 2026. The slide since then reflects real momentum from competitors, not just statistical noise.
Gemini’s growth is largely tied to Google’s ecosystem. When your AI assistant is baked into Gmail, Google Docs, and Android, user numbers follow. Claude’s growth is a different story. Anthropic has built a strong reputation for productivity use cases, and its user retention rate is closing in on ChatGPT’s, which is a harder number to build than raw downloads.
One data point from the report is especially worth noting: OpenAI’s deal with the U.S. Department of Defense in February triggered a measurable spike in app uninstalls. That suggests users are paying attention to the companies behind these tools, not just the tools themselves. Brand trust is now a competitive variable in the AI market, not just a PR concern.
On the money side, the industry is clearly shifting gears. Sensor Tower estimates that in the first half of 2026, people will download nearly 2.3 billion AI apps and spend over $4.2 billion on them. That compares to $1.83 billion in spending during the same period in 2025. Growth rates for both downloads and spending have slowed, which points to a market that is maturing rather than exploding. The race to acquire users at any cost is giving way to a harder question: which of these companies can actually build lasting revenue?
Claude may have the best early answer. Thirteen percent of Anthropic’s users are paying subscribers, the highest conversion rate in the industry. For investors trying to figure out which AI businesses are worth backing long-term, that number matters more than monthly active user counts.
Regionally, Asia recorded its first download decline in Q1 2026, down 3.3%, driven by dips in China and India. Despite leading globally in total downloads, Asia still trails North America and Europe in in-app spending. That gap will influence where companies choose to focus their premium features and paid products over the next few years.
In the U.S., users are leaning into AI for productivity tasks and are increasingly willing to pay for it. Average revenue per user has grown across the industry, and time spent on AI apps is on track to roughly double: from 17.2 billion hours in H1 2025 to around 36 billion hours in H1 2026. The top three assistants, ChatGPT, Gemini, and Claude, account for 89% of that time. Adjacent categories like AI companions and AI content generation tools remain fragmented, with no clear leader yet.
OpenAI has also started running ads inside ChatGPT. By May, about 17% of daily users were seeing them. The largest advertiser categories so far are software and shopping, followed by media and entertainment, and food and dining. It is an early experiment, but it signals that OpenAI is serious about building revenue streams beyond its subscription plans.
The shopping angle is one to watch closely. ChatGPT is increasingly sending referral traffic to retailers like Target, Walmart, and Costco. Amazon has blocked ChatGPT’s web crawlers, which has kept its referral traffic from the platform flat. That is an opening competitors are starting to use. Walmart’s in-app AI assistant, Spark, has been gaining users while Amazon’s Rufus has seen flat growth. Sensor Tower did note that Amazon shoppers who used Rufus spent more time in the app and converted at higher rates than those who did not, which suggests on-platform AI can influence buying behavior when users actually engage with it.
The broader picture is this: the AI assistant market is no longer a one-horse race. ChatGPT is still the leader, but the lead is shrinking, users are switching more freely, and the companies that figure out monetization first will have a real advantage in the years ahead.
