AI sends people to pages that don't exist 2.87x more often than Google
An AI assistant recommends you, a customer clicks, and they land on a page that is not there. It happens more than owners think. Ahrefs studied 16 million URLs cited by six AI assistants and reported on September 2, 2025: "We found that AI assistants send visitors to 404 pages 2.87x more often than Google Search" (ahrefs.com). ChatGPT was the worst offender, with 1.01% of clicked URLs returning a 404. Your 404 page is no longer a technical footnote. It is a door AI traffic walks through, and most sites leave it bare.
Where the dead links come from
AI assistants mix live web search with their own memory, and their memory is imperfect in two specific ways. Some remembered URLs were real once, then got deleted or moved without a redirect. Others never existed at all: the assistant invents a path that merely sounds plausible. In the Ahrefs study, assistants produced links like /blog/internal-links/ on the Ahrefs site itself, a page that was never real, because it sounds like something that should exist.
The rates are small in percentage terms and large in consequence. Across all six assistants, 0.43% of cited URLs returned a 404, against Google's much lower baseline. ChatGPT cited dead URLs 2.38% of the time. The absolute numbers grow with every month of AI referral traffic, and unlike a ranking problem, this failure happens after you already won.
What a dead landing page costs
Walk it through from the customer's side. They asked an assistant for a recommendation. Out of everything it could have said, it named you. They clicked. Your server answered: nothing here. There is no colder way to greet the warmest kind of visitor. You paid nothing for that referral, and it still cost you a customer.
A technical SEO audit that skips the 404 experience misses the exact spot where this traffic dies. Rankings did not fail. Content did not fail. The doorway failed.
The fix, in order
- Return a real 404 status for unknown URLs. Not a redirect to the homepage, not a soft page that answers 200 and pretends all is well. Machines need the honest status code to stop citing the dead path.
- Make the 404 page read the way back: your main pages linked, plain words, a way to search or navigate. A visitor who hit a dead end should see the exit in one glance.
- Watch your logs or your analytics 404 report for invented URLs that keep drawing visitors. If a hallucinated path gets real traffic, redirect it to the page those visitors actually wanted. Ahrefs' study recommends the same move.
- When you delete or move a page, redirect the old URL. The deleted-without-redirect class of dead link is the one you caused, and the one you can end today.
We got caught on this one too
Receipts, since we grade other people's sites. On July 10, 2026, an outside checkup caught auditlamp.com failing this exact test: our branded 404 page existed in the codebase but was never wired up, so visitors on unknown URLs got a bare machine response. We shipped the fix the next day, and the same week we added a 404-experience check to our engine. Every scan now grades whether unknown URLs return a real 404 status and whether the page shows a way back.
Check your own doors
Our free Visibility Scan reads your whole site, up to 150 pages, the way Google and the AI engines read it, and checks it against our 164 graded checks, the 404 experience among them. Every failing check named, worst first. Two fresh scans per site each month. No email required to get your diagnosis.
Sources: Ahrefs, "How Often Do AI Assistants Hallucinate Links? (16 Million URLs Studied)," September 2, 2025 (ahrefs.com).