ChatGPT Links Lost UTM Tags After GPT-6, Shifting About 26,000 Daily Visits to Direct in One Sample

Ras Al Khaimah, United Arab Emirates, 17 October 2026.

Links in ChatGPT answers stopped carrying the utm_source=chatgpt.com tag and the referrer for about a week after OpenAI rolled out GPT-6, causing analytics tools to log many ChatGPT visits as direct traffic, according to data from Adobe's Cedric Huesler reported by Search Engine Roundtable, Search Engine Land and Search Engine Journal from 14 October 2026. Huesler later wrote that OpenAI had told him it was a bug and that a fix began rolling out on 15 October. OpenAI has not published a statement.

For SEO and analytics teams, the practical effect is a dip in reported ChatGPT referrals for roughly 8 to 15 October that may not reflect any real loss of visits.

What happened

OpenAI announced GPT-6 on 7 October 2026. It began rolling out to paid plans that day and expanded to Free and Go users on 8 October. OpenAI's announcement says GPT-6 makes better decisions about when to search the web, but it does not mention how links or citations are displayed.

According to Search Engine Roundtable, Huesler found that GPT-6 opened links with a browser setting that withholds both the UTM tag and the referrer. With neither signal present, tools such as Google Analytics have no way to attribute the visit to ChatGPT and file it as direct.

Key findings

Huesler's analysis, as reported by the three publications, looked at about 500 pages where ChatGPT had driven at least 5% of visits, comparing 9 to 13 October with the week before.

Metric (about 500 pages, 9 to 13 Oct vs prior week)	Change reported
ChatGPT-attributed visits	Down about 31,000 a day
Direct visits on the same pages	Up about 26,000 a day
Search visits on the same pages	Down 7%, in line with the site-wide trend
Pages that lost ChatGPT visits and gained direct visits	About two in three

The gap between the two main figures (31,000 lost, 26,000 gained) leaves about 5,000 visits a day unaccounted for in this sample. Search Engine Journal noted that it is not yet clear whether all of the missing traffic was relabelled or whether some was lost.

Search Engine Journal also cited several AI search analytics firms. One reported ChatGPT sessions in Google Analytics 4 falling between 22% and 57% from 9 October across the sites it tracks. Another found the share of cited ChatGPT answers containing at least one tagged link fell from about 98% on 8 October to 66% on 14 October. Search Engine Journal pointed out that these firms sell AI search services and that some did not publish sample sizes.

The fix

Search Engine Journal reported that Huesler said OpenAI confirmed the bug on 14 October and that a fix started rolling out early on 15 October. By 9 a.m. Pacific Time that day, tagged ChatGPT clicks were back to about 95% to 100% of the same hour a week earlier across thousands of domains he tracks. Search Engine Roundtable updated its own report on 15 October to say the tags appeared to be returning.

Huesler also said most ChatGPT clicks still arrive without a referrer, so the UTM tag is now the main way to identify them. Search Engine Journal reported that at least one other practitioner had not yet seen the change on his own accounts.

We checked OpenAI's ChatGPT release notes on 17 October. Entries for 1 to 16 October cover GPT-6, Intelligent UI, slides, voices and other features. None mentions link tracking, UTM parameters or a referrer fix.

What this means for SEO teams

• Annotate 7 to 15 October in your reports. Mark the window in GA4, Looker Studio or whatever dashboards you share, so a ChatGPT dip is not read as lost visibility. Huesler's own working window, per Search Engine Journal, is 8 to 15 October.
• Compare ChatGPT and direct side by side by landing page. Pages that historically drew ChatGPT traffic and show a matching rise in direct visits are likely affected by attribution, not demand.
• Segment on the UTM tag, not the referrer. With most clicks lacking a referrer, a channel rule that only checks for chatgpt.com as the source domain will undercount. Add a rule for utm_source=chatgpt.com.
• Do not change strategy on one week of data. The drop coincides with a model launch, an interface change and a reported tracking bug. Wait for at least two clean weeks after 15 October before drawing conclusions.
• Check your own paid links separately. Search Engine Journal reported that UTM parameters on advertisers' own ChatGPT Ads links should not have been affected.

Conclusion

For roughly a week after GPT-6 launched, ChatGPT sent many visitors without the utm_source tag or a referrer, and analytics tools counted them as direct traffic. One analysis of about 500 pages found ChatGPT visits down about 31,000 a day while direct visits rose about 26,000 a day on the same pages.

A fix began rolling out on 15 October, according to Adobe's Cedric Huesler, who said OpenAI described the issue as a bug. OpenAI has not commented publicly or mentioned it in its release notes, so teams should annotate the period and verify recovery in their own data.

Questions and answers

Why did ChatGPT referral traffic drop in October 2026?

After GPT-6 rolled out from 7 October, links in ChatGPT answers opened without the utm_source=chatgpt.com tag or a referrer, according to analysis by Adobe's Cedric Huesler reported by Search Engine Roundtable and Search Engine Journal. Analytics tools then counted those visits as direct.

How large was the effect?

In Huesler's sample of about 500 pages where ChatGPT drove at least 5% of visits, ChatGPT visits fell by about 31,000 a day and direct visits rose by about 26,000 a day between 9 and 13 October compared with the prior week.

Has OpenAI fixed it?

Huesler said OpenAI described it as a bug and that a fix began rolling out on 15 October, with tagged clicks back to about 95% to 100% of the prior week's level that morning. OpenAI has not published a statement, and its release notes do not mention it.

What should analytics teams do?

Annotate 7 to 15 October in reports, compare ChatGPT and direct traffic by landing page, and identify ChatGPT visits by the utm_source=chatgpt.com tag rather than the referrer.

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