ChatGPT referral traffic drop traced to a tracking bug, not lost visitors
ChatGPT-attributed sessions in Google Analytics 4 fell sharply for many sites from October 9, and the cause appears to be a tracking change rather than a real loss of visitors. Graphite CEO Ethan Smith reported declines of 22% to 57% across sites with meaningful AI Assistant traffic, which he put at roughly 45% below the previous baseline. LLM Pulse measured about 46% fewer ChatGPT sessions on October 9 to 11 against the same days a fortnight earlier, while total traffic on those sites held steady.
The change came after the GPT-6 rollout. ChatGPT began opening links in the answer text in a new tab without the utm_source=chatgpt.com tag or a referrer, so those visits land in GA4 as Direct. Smith said inline links lost the tag while links in the Sources panel and shopping links kept it, and that 95% of mobile ChatGPT visits to Graphite's sites relied on the tag alone. Profound found the share of cited answers containing at least one tagged source link fell from about 98% on October 8 to 66% by October 14, as its Intelligent UI answer format grew from 2% to about 35% of collected answers.
Adobe senior director of product management Cedric Huesler compared October 9 to 13 with the prior week across about 500 pages where ChatGPT drove at least 5% of visits. ChatGPT visits fell by roughly 31,000 a day while Direct visits rose by about 26,000 a day, and the new Direct visitors behaved like ChatGPT visitors. Huesler said OpenAI confirmed on October 14 that the missing tags were a bug, and that a fix began rolling out early on October 15, with tagged clicks back to 95% to 100% of the same hour a week earlier across thousands of domains. He still recommends counting the UTM tag rather than the referrer.
For brands tracking AI referrals, the practical step is to annotate October 8 in reporting before anyone reads the drop as lost interest, and to review ChatGPT and Direct traffic side by side for each page ChatGPT referred visitors to, plus the homepage, where Peec AI's Tomek Rudzki found 54% of the direct URLs ChatGPT displayed. Restoring the tags will not recover attribution already lost.
Reported by Search Engine Journal ↗
Topics: ChatGPT, Measurement, Citations