Google’s Gemini eats into ChatGPT’s market share, Grok overtakes Perplexity
ChatGPT is still a major player, but Google is eating significantly into its market share with Gemini. That’s what the new Global AI Tracker from SimilarWeb shows. The analysis of global website traffic shares for generative AI services reveals a clear trend: ChatGPT’s initial quasi-monopoly is eroding continuously, while Google in particular is catching up significantly with Gemini.
It’s worth noting that this analysis is based solely on web traffic and does not include usage of native apps for smartphones, tablets, and notebooks. This means it’s unclear how intensively ChatGPT and competitors are being used on iPhones or Android phones.
OpenAI Under Pressure: From 86.7 to 64.5 Percent
ChatGPT from OpenAI remains the undisputed market leader at 64.5 percent, but is systematically losing ground. Within twelve months, market share shrank by more than 22 percentage points – from 86.7 percent at the beginning of 2025 to currently 64.5 percent. The decline was particularly dynamic over the past six months, during which ChatGPT lost almost 15 percentage points.
This development reflects the increasing maturity of the market. What initially appeared as a first-mover advantage is evolving into a competitive environment with multiple established providers. OpenAI faces not only technological competition but also the challenge of defending its pioneering position against competitors with sometimes significantly greater resources.
Google’s Catch-Up: Quadrupling in One Year
The most remarkable winner of the past twelve months is undoubtedly Google with its AI assistant Gemini. Market share nearly quadrupled from 5.7 percent to currently 21.5 percent. With this, Gemini crossed the symbolically significant 20 percent mark for the first time.
The development in the second half of 2025 was particularly impressive: while Gemini was still at 8.6 percent six months ago, the service reached 18.2 percent by the end of 2025 – a gain of more than double. The integration into Google’s ecosystem, from search to Android to Workspace applications, gives the company structural advantages in user acquisition.
The figures suggest that Google has overcome its initial difficulties in generative AI – such as the problematic launch of Bard – and is now benefiting from its market power and technological infrastructure.
The Middle Field: Shifts Between Grok and Perplexity
Below the two dominant players, remarkable changes are also taking place. Grok from xAI, Elon Musk’s AI company, increased its market share from zero to 3.4 percent within a year. Just three months ago, Grok had already crossed the 2 percent mark, and growth has accelerated since then.
The integration into the social media platform X (formerly Twitter) and the high-profile positioning by Musk himself likely contributed to this development. At 3.4 percent, Grok now ranks nearly on par with DeepSeek (3.7 percent), the Chinese AI provider that was significantly ahead of Grok six months ago (4.8 percent).
Perplexity, the search-focused AI service, shows stagnating development by contrast. After reaching a peak of 2.4 percent three months ago, market share fell to currently 2.0 percent – and for the first time in months is again behind Grok. A year ago, Perplexity at 1.9 percent was still ahead of all emerging competitors.
This shift indicates intense competition in the middle field, where differentiation of offerings is becoming increasingly decisive. While Perplexity positions itself as a specialized search service, Grok may be benefiting from its broader focus and connection to the X platform.
Anthropic and Microsoft: Stable Niche Positions
Claude from Anthropic and Microsoft’s Copilot remain largely stable in their positions. Claude has held steady at around 2.0 percent for months, while Copilot at 1.1 percent is even slightly declining – remarkable given its tight integration into Microsoft products and strategic partnership with OpenAI.
