ChatGPT Dropped UTM Tags From Links for About a Week

ChatGPT stopped attaching UTM tags to outbound links for nearly a week in early October. Search Engine Roundtable reported the issue on October 14. The problem appears to have started around the time GPT-6 launched.

Since June, OpenAI had automatically added a utm_source=chatgpt.com tag to links shared in ChatGPT answers. That tag let site owners separate ChatGPT visits from search or social traffic in their analytics. Once GPT-6 rolled out in early October, the tag disappeared and referrer data stopped coming through as well.

Adobe's Cedric Huesler noticed the change while reviewing his own site's traffic. He found that GPT-6 opens links in a way that strips referrer information, which left analytics tools with nothing to work with. Without a tag or a referrer, he said, a tool has no choice but to file the visit as direct.

Huesler compared about 500 pages where ChatGPT accounted for at least 5% of visits, looking at October 9 to 13 against the prior week. ChatGPT visits fell by roughly 31,000 a day, while direct visits rose by about 26,000 a day. Search visits dropped 7% over the same stretch.

Among pages that lost ChatGPT traffic, the share that also saw a rise in direct visits jumped from about half the week before to roughly two-thirds. The newly arrived direct visitors behaved almost indistinguishably from known ChatGPT visitors, Huesler noted, with similar time on page and navigation patterns.

OpenAI never issued a public statement on the issue. Huesler updated his post on October 15 with a note of relief, saying it had been a bug and that ChatGPT links were tagging again.

Search Engine Roundtable's Barry Schwartz said he wasn't initially sure whether the change was intentional or just a coding error. Since OpenAI quietly reversed it without any announcement, a similar gap could resurface without warning.

Any site that tracks ChatGPT-driven traffic solely through UTM tags likely undercounted it during that missing week, since the affected visits would have shown up as direct instead.

In Korea

If direct traffic looked unusually high over the past week or two, it's worth cross-checking landing pages and visit timing to see whether some of it was really coming from ChatGPT.

Source: Search Engine Roundtable, October 14, 2026. Checked October 19, 2026. Read the original