AI chatbot traffic share, August 2025 to August 2026

Similarweb publishes monthly estimates of worldwide website traffic share across the largest generative AI chatbots. Comparing August 2026 with August 2025 shows a market that has spread out quickly.

What stands out

• ChatGPT fell from 73.3% to 55.5%, a drop of 17.8 points, while remaining the largest.
• Gemini roughly doubled, from 12.9% to 25.6%.
• Claude grew from 1.9% to 9.3%, close to fivefold, the fastest rise in the set.
• DeepSeek, Copilot and Perplexity each ended lower than a year earlier, Perplexity from 2.0% to 0.9%.

What it means for brands

A brand that is measured on one assistant is now looking at less than the whole picture. Tracking across several platforms, and treating each one's behaviour separately, has become the sensible default.

A second Similarweb view: the twelve months to May 2026

Similarweb's 2026 Generative AI landscape report covers a slightly different window, June 2025 to May 2026, and gives a picture that agrees in direction with the August comparison above. It reports ChatGPT's share of worldwide generative AI web traffic sliding from roughly 76% a year earlier to around 53%, Gemini rising from under 9% to about 27 to 28%, and Claude moving from barely 2% to close to 9%. The two snapshots are one quarter apart and use different comparison months, so the numbers differ slightly. They tell the same story.

The growth figure matters as much as the shares. Average monthly web visits to generative AI platforms reached 9.5 billion over the twelve months, up 70% from 5.6 billion in the preceding twelve months. A market growing that fast can change share sharply even when the leader is also growing, so a falling share does not mean falling use.

Why share moved: what the data can and cannot say

Similarweb reports what happened, not why. Plausible contributors include new model releases, distribution through operating systems and browsers, and bundled offers, but the reports we cite do not attribute the movement to any of them, and we do not either. What can be said is that the leader's lead narrowed, that two challengers grew faster than the market, and that the smaller platforms lost share.

What website traffic leaves out

What a brand team should take from it

1. 1Track more than one assistant. The leader is still the largest, but no single platform is the whole audience.
2. 2Weight your effort by where your customers are, using your own analytics and customer research, not only by global share.
3. 3Recheck the picture every quarter. Shares moved by double-digit points in a year.
4. 4Treat citation and source behaviour as platform-specific. Similarweb's data on citations in US ChatGPT prompts shows how much it varies by category.

Similarweb's measure is the presence of citations in US ChatGPT prompts, so it says how often a source link appears at all, not which brands are named. The spread between categories is the useful part: whether an answer shows sources depends heavily on the kind of question being asked.