Graphite puts AI at 76 billion monthly sessions and drops its search comparison

Graphite is a content agency that measures AI assistant usage using session data from Similarweb. Its updated State of Gen AI report counts 76 billion sessions a month across six AI assistants. That is the September figure. It is 37 percent more than a year earlier.

Matt G. Southern at Search Engine Journal covered the report. The numbers below are from Graphite, as Search Engine Journal relays them. Similarweb provided the underlying measurements.

The number that is gone

Graphite's March report put AI sessions at 56 percent of search worldwide, and 34 percent in the US. The new report takes that comparison out. Graphite says it "can no longer reliably compare" AI usage with search. The March count "likely undercounted Google search use from Google's Android app". Graphite says it has "no reliable data source" for what share of those Android app sessions is general search.

The headline AI-versus-search ratio that circulated all year is now withdrawn by the agency that produced it.

The new numbers for September

Six AI assistants are in the count. Graphite's total is 76 billion sessions a month worldwide, up from 56 billion in March.

ChatGPT holds 60 percent of worldwide AI assistant sessions and 66 percent in the US, by Graphite's measure. Claude is 10 percent worldwide and 11 percent in the US. Gemini is 14 percent worldwide and 10 percent in the US.

Claude grew 1,901 percent year over year, the biggest percentage change of the six. Graphite says Claude generated 26 percent of the new sessions added over the year. ChatGPT grew 24 percent and generated 58.9 percent of the new sessions. ChatGPT is so much larger to begin with. Perplexity dropped 27 percent and was the only one of the six that shrank.

Nine of every ten sessions worldwide were on mobile, either the mobile app or the mobile web, in Q3 2026. The US share was 78 percent.

What the report says about AI traffic to websites

The piece a search team cares about is different from the headline. Graphite reports that AI accounts for less than 1 percent of the average website's traffic. Organic search sends 49 times as much traffic as AI referrals, and paid search sends eight times as much. The reference period is the second quarter of 2026 in the US.

AI referral traffic is still growing fast. Graphite puts the year-over-year growth at 92 percent worldwide and 75 percent in the US, both measured in July.

What a working SEO reader does with this

Take the "AI is 56 percent of search" line out of any client dashboard that carries it. The agency that produced that figure has retracted it. The honest AI traffic number today is under 1 percent of site visits. The base is small, and growing fast.

The other change is that the measurement itself has an edge. Graphite says mobile app sessions are the piece it cannot audit cleanly. Most of the AI session count sits there. A report using the same data in six months may move the headline again.

Source

• Report Puts AI At 76B Monthly Sessions, Drops Search Engine Comparison, Matt G. Southern, Search Engine Journal
• The State of Gen AI Report, Graphite