Graphite Drops AI-to-Search Comparison as Google App Data Complicates Counts
Graphite’s latest report estimates that six AI assistants generated 76 billion monthly sessions worldwide in September 2026, a 37% increase from a year earlier. But the agency no longer compares that activity with search-engine use, saying it cannot reliably separate general search from other activity in Google’s Android app.
The change affects how marketers should interpret AI’s scale relative to search. Graphite’s March report had estimated AI sessions at 56% of worldwide search activity and 34% in the United States. It also estimated that search-related use represented 28% of AI sessions globally and 17% in the U.S. The updated report says the earlier comparison likely undercounted Google use because it did not include sessions in the Android app.
Why the comparison changed
The March analysis counted search-engine website visits, rather than app sessions, on the basis that search apps saw little use. Graphite’s November report identifies Google’s Android app as a significant exception: Similarweb estimates that it generated 11.8 billion monthly sessions in the U.S.
Those sessions do not all represent conventional search. People also use the app for image recognition, translation and Google Discover. Graphite says it has no reliable data source for determining what share of the app’s activity is general search. Without that distinction, the agency says it can no longer reliably compare AI use for search with search-engine use.
The report’s session totals combine estimated website visits and mobile app sessions, using data from Similarweb. Desktop applications are excluded because reliable data is not available for them. Graphite provides SEO and answer-engine optimization services; Similarweb provides the underlying data.
Because the new report does not update the March search comparisons, those earlier figures remain visible on the March report page, alongside a link to the newer analysis. Marketers using the ratios should therefore note that the earlier search count was based on a narrower measure of Google activity.
AI referrals remain a small share of site traffic
Graphite’s report says AI accounts for less than 1% of website traffic on average, even as referrals from AI services grow. Worldwide AI referral traffic to the sites measured rose 92% year over year as of July 2026; the U.S. increase was 75%.
For U.S. traffic in the second quarter of 2026, the report’s comparison puts organic search volume at 49 times AI referrals and paid search at eight times AI referrals. These figures concern visits sent to websites, not the total volume of sessions within AI assistants—a distinction that matters when comparing channel activity.
The referral analysis covers the top 43,000 sites among domains that recorded at least 100,000 monthly U.S. visits in six or more months between July 2023 and July 2026. In July, ChatGPT accounted for 60% of AI referrals worldwide, followed by Gemini at 14% and Claude at 10%. In the U.S., ChatGPT’s share was 66%, while Claude had 11% and Gemini 10%.
Graphite also notes that some visits prompted by AI answers may be attributed to direct traffic or branded search rather than AI referrals. Those visits would not appear in a referral measure that relies on identifiable AI sources. The report cites early evidence that branded search traffic is fairly flat year over year, with fuller results still to come. In U.S. desktop data, 55.9% of visits to a brand’s website after a ChatGPT recommendation came through branded search.
Growth varies across assistants
Activity across the six assistants increased 2.3% worldwide from July to December 2025, a period the report characterizes as a plateau. From January through September 2026, global activity rose 19%. U.S. session activity was up 45% year over year in September.
ChatGPT’s worldwide sessions grew 24% year over year and accounted for 58.9% of sessions added. Claude recorded the largest percentage increase, rising 1,901% globally and contributing 26% of additional sessions. Perplexity was the only assistant in the group to decline, down 27% worldwide. Mobile app and mobile web sessions made up 89% of global activity in the third quarter of 2026, compared with 78% in the United States.
For channel planning, the report’s central implication is methodological: an AI-to-search ratio depends on what counts as search and which app activity can be classified. OpenAI’s estimate that ChatGPT receives about one-fifth as many search-like queries as Google uses a different measure, counting a search when a question sends ChatGPT to the web. Graphite’s figures count visits and app sessions. The two estimates should not be treated as directly interchangeable.
