March 14, 2026 — AI assistants now command 56% of global search volume with 45 billion monthly sessions, according to a Graphite.io study analyzing Q4 2025 data across major platforms like ChatGPT and Gemini.
The report, “AI Is Much Bigger Than You Think,” by CEO Ethan Smith, shows AI usage equals 34% of U.S. search volume (5.4 billion sessions) and emphasizes that prior web-only estimates understated AI activity by 4-5x due to 83% of global AI sessions occurring via mobile apps.
Key Study Findings
Total search plus AI usage grew 26% worldwide year-over-year, indicating non-zero-sum expansion rather than cannibalization of traditional search. Search-related AI prompts represent 28% of global search volume. ChatGPT holds 89% of the AI market share worldwide.
Monthly sessions of AI are now 56% the size of search worldwide and 34% in the US, 4x-5x larger than previous reports that only include web data.
AI now receives 45B monthly sessions worldwide, and 5.4B monthly sessions in the US.
(Excerpt from Ethan Smith’s X post).
The study used Similarweb data for web and mobile sessions from top AI tools and search engines, adjusting for 51.6% “asking” prompts as search-like.
Marketing Implications
Industry outlets stress the need for both SEO and AEO. Ignite Visibility’s March 13, 2026, roundup noted: “AI assistants (e.g., ChatGPT, Gemini) account for up to 56% of global search volume… you cannot avoid AI search when planning your SEO strategy.”
Search Engine Land quoted Smith: “It’s not SEO vs. AEO — you need both LLM visibility and traditional rankings.”
AI Assistants Dominate 56% of Global Search Volume, as the Graphite.io study highlighted in Ignite Visibility’s weekly roundup reveals, with AI tools like ChatGPT and Gemini handling 56% of worldwide search volume (45 billion monthly sessions), compared to 34% in the U.S. This shift is reshaping SEO and digital marketing strategies globally.
Coverage and Buzz
The findings gained traction starting March 9, 2026, via Search Engine Land, with additional reports from Performance Marketing World and others noting 28% search-like prompts.
AI Assistants Dominate 56% of Global Search Volume, per the study, underscoring mobile app dominance and growth. Smith shared on X: “AI is much bigger than I thought.”
For more on SEO shifts, see related insights.