AI tools now generate 45 billion monthly sessions worldwide — about 56% of search engine volume, according to a study by Graphite.io CEO Ethan Smith. This marks a significant shift in how users discover information online.
The Scale of AI Discovery
The analysis combines web traffic and mobile app usage across major AI tools and estimates AI activity equals 56% of global search usage and 34% in the U.S. Much of this growth is occurring in mobile apps such as ChatGPT, Gemini, Perplexity, Grok, and Claude.
Key findings from the report:
- AI platforms generate 45 billion monthly sessions worldwide
- In the U.S., AI accounts for 5.4 billion monthly sessions
- 83% of global AI usage occurs inside mobile apps (75% in the U.S.)
- ChatGPT dominates AI usage, representing 89% of global AI sessions
Search-Like Prompts
When isolating search-like prompts (“asking”), AI usage equals 28% of search worldwide and 17% in the U.S. The report excludes prompts categorized as “doing” or “expressing.” According to OpenAI research, about 52% of prompts are information-seeking — the closest equivalent to traditional search queries.
Methodology and Critique
Most projections comparing AI to search use web traffic alone, typically comparing Google.com visits with ChatGPT website traffic. This analysis argues these comparisons underestimate AI activity by 4–5x because most usage occurs in mobile apps.
Rand Fishkin, co-founder of SparkToro, posted a rebuttal questioning the methodology in a LinkedIn post, noting that ChatGPT represents only about 3% of desktop web search.
What This Means for Marketers
AI is expanding discovery, not shrinking search demand. Total usage across search engines and AI assistants has grown 26% globally since 2023. In other words, it’s not SEO vs. GEO — you need both traditional rankings and LLM visibility to reach audiences effectively.