March 15, 2026 — A Graphite.io study has found that AI assistants dominate global search, handling 56% of worldwide queries, based on Q4 2025 data showing 45 billion monthly AI sessions globally, equivalent to 56% of traditional search engine volume worldwide and 34% in the US.
The report, titled “AI Is Much Bigger Than You Think” and authored by CEO Ethan Smith, analyzed sessions from platforms including ChatGPT, Gemini, Perplexity, Grok and Claude. It reported 5.4 billion US sessions, with 83% of global AI usage and 75% in the US occurring in mobile apps, which were previously undercounted in web-only estimates.
Key Statistics and Adjustments
ChatGPT leads with 89% global market share (86% in the US). Adjusting for “search-like” asking prompts—which comprise 51.6% of usage per OpenAI/Harvard data—AI represents 28% of global search volume (17% in the US).
Total discovery volume, combining search engines and AI asking prompts, grew 26% year-over-year worldwide and 16% in the US, indicating expansion rather than replacement.
“AI is expanding discovery, not shrinking search demand,” Smith told Search Engine Land.
Coverage and Reactions
The findings, covered in Ignite Visibility’s digital marketing news roundup (March 7-13) and Search Engine Land (March 9), highlight shifts in SEO and digital marketing. Additional reports from ALM Corp, Performance Marketing World and Lazysoft echo that AI assistants dominate global search, handling 56% of worldwide queries.
SEO expert Aaron Haynes posted on X: “AI usage isn’t 5% the size of search. It’s 56% worldwide… The pie is getting bigger.” [7]
Implications for Marketers
Smith noted the rapid AI growth, with US AI usage up 300% from December 2024 to 2025, though worldwide sessions plateaued since July 2025. The study underscores that AI assistants dominate global search, handling 56% of worldwide queries, urging adaptation in SEO strategies.
“We found that not only are the claims that AI may soon overtake search not overstated, they are understated,” Smith wrote in the original study.
This development signals a larger discovery ecosystem, as AI assistants dominate global search, handling 56% of worldwide queries without diminishing traditional search.