If your analytics showed fewer visits from ChatGPT in mid-October, and more "direct" visits at the same time, your site probably did not lose visitors. Most of them were labeled wrong. Adobe's Cedric Huesler says OpenAI told him it was a bug, and a fix started on October 15.
What happened
ChatGPT adds a tag to the links it cites: utm_source=chatgpt.com. OpenAI's publisher FAQ says this tag lets publishers track ChatGPT traffic in tools such as Google Analytics. The tag has been on ChatGPT citations since ChatGPT search launched in 2024.
Search Engine Journal reports that after the GPT-6 rollout (October 7-8), ChatGPT opened links without this tag. It also opened them in a way that sends no referrer, the other signal that tells analytics where a visit came from. With no tag and no referrer, analytics tools counted many ChatGPT visits as direct traffic.
Huesler looked at about 500 pages where ChatGPT brought at least 5% of visits. He compared October 9-13 with the week before:
- ChatGPT visits: down about 31,000 per day.
- Direct visits: up about 26,000 per day on the same pages.
So most of the "lost" ChatGPT visits seem to have moved to direct.
The fix
Huesler says OpenAI confirmed to him on October 14 that it was a known bug. He says the fix started to roll out early on October 15. By 9 a.m. Pacific time that day, tagged ChatGPT clicks were back to about 95-100% of the same hour a week earlier, across the thousands of domains he tracks.
This confirmation is secondhand. OpenAI has not published a statement, and its ChatGPT release notes for October 1-15 do not mention the bug or the fix.
What to do
- Add an annotation for October 8-15. In GA4, right-click a point on a line graph and choose "Add annotation." You can pick a date range. Then nobody misreads the dip later.
- Compare ChatGPT and direct traffic for those days. If ChatGPT went down and direct went up on the same pages, this bug is the likely cause.
- Do not expect GA4 to fix old data. Visits that arrived with no tag and no referrer stay in direct.
- Keep the UTM tag as your main signal. Huesler says most ChatGPT clicks still arrive with no referrer, so utm_source=chatgpt.com is the best way to count them.
Check that your analytics is installed
You can only see ChatGPT visits if your site has an analytics tool. The SEOSFT Tracking check reads your homepage and shows which tools it finds: Google Analytics 4, Google Tag Manager, ad pixels and a consent banner. It does not check UTM tags or referrers.
Sources
- Search Engine Journal, ChatGPT Traffic Drop Appears To Be A Tracking Problem: https://www.searchenginejournal.com/chatgpt-traffic-drop-appears-to-be-a-tracking-problem/593157/
- OpenAI Help Center, Publishers and Developers FAQ: https://help.openai.com/en/articles/12627856-publishers-and-developers-faq
- Google Analytics Help, About annotations: https://support.google.com/analytics/answer/15884203