Gemini is rapidly eating into ChatGPT’s traffic share—and is turning what was essentially a monopoly into a two-player race.
According to the latest data from SimilarWeb from December 5, ChatGPT’s dominance in the generative AI market has fallen to 68.0%, marking the first time OpenAI’s flagship product has dropped below the 70% threshold. Meanwhile, Google’s Gemini has surged to 18.2%, nearly quadrupling its market share from just 5.4% twelve months ago.
The shift represents a dramatic reshaping of the generative AI landscape. A year ago, ChatGPT commanded 87.2% of traffic share, effectively operating as a near-monopoly in the consumer AI space. That 19.2 percentage point erosion over twelve months signals not just gradual market maturation, but an accelerating fragmentation as competitors find their footing.
Gemini’s ascent has been particularly striking in recent months. The platform has added 4.5 percentage points of market share in just the past month alone, jumping from 13.7% in November to 18.2% in early December. This momentum appears to be directly cannibalizing ChatGPT’s user base rather than simply capturing new entrants to the market.
The diverging trajectories highlight Gemini’s remarkable turnaround over the past six months. After a sluggish start to 2025, Google’s AI assistant has gained momentum through a series of strategic product releases that have resonated with users. The launch of the Nano Banana image generation model in mid-2025 gave Gemini a creative edge, allowing users to generate high-quality images directly within the platform. This was followed by the release of Gemini 3 Pro, which significantly improved the chatbot’s reasoning capabilities and response quality, and most recently, Nano Banana Pro, which further enhanced image generation with more refined controls and faster processing times.
Beyond the two-horse race emerging at the top, other players are showing signs of life. Grok, the AI assistant from xAI, has steadily climbed from 2.1% six months ago to 2.9% today, demonstrating consistent if modest growth. Perplexity has carved out a 2.1% share by positioning itself as an AI-powered search engine rather than a pure chatbot, appealing to users seeking researched, cited answers. Claude, Anthropic’s AI assistant, has also shown growth, moving from 1.6% a year ago to 2.0% today, though its trajectory has been more gradual than some competitors.
Notably absent from recent momentum is DeepSeek, which surged to 5.3% six months ago but has since retreated to 3.9%. Microsoft’s Copilot has remained largely stagnant at 1.2%, despite the company’s significant investments in OpenAI and integration across its product suite.
The data suggests the generative AI market is entering a new phase. What began as a ChatGPT-dominated landscape is evolving into a more competitive ecosystem where product differentiation, feature velocity, and integration capabilities matter. Gemini’s trajectory poses a interesting question: is 20% market share just a waypoint, or will ChatGPT’s network effects and first-mover advantage ultimately stabilize its position? If current trends hold, we could see Gemini approaching the 20% benchmark within weeks, transforming the competitive dynamics of an industry that, until recently, appeared to have a clear and unassailable leader.