A third of web pages published since ChatGPT’s launch show signs of AI authorship, study finds

Over one-third of web pages published after the release of ChatGPT show signs of being written by AI, according to a new study from Pew Research released on Thursday. The report corroborates other studies that detail how much of the web’s newer web pages are now either written by or “substantially edited” by AI, the firm says.

It also arrives shortly after internet infrastructure provider Cloudflare reported that bot web traffic had overtaken human web traffic — a milestone that was reached sooner than the company had estimated.

Pew’s data, however, is focused not on who or what is browsing the web, but on what is being browsed. And apparently, much of it is bots reading web pages written by other bots.

To compile the report, Pew said it used the Common Crawl web archive to collect nearly half a million English-language web pages from the past five or so years, starting a couple of years before ChatGPT’s November 2022 release. Pew then used Open Pangram’s technology to detect how many were likely written or heavily edited by AI.

In a random sample of 10,000 web pages collected in July 2026, around 10% showed “significant signs of AI authorship,” Pew said.

However, Pew pointed out that a random sample like this would inevitably include older web pages — ones published before AI writing tools even existed, and therefore couldn’t have been AI written.

To get a better sense of how much of the web is now being written by AI, Pew filtered out the older web pages and focused only on those published after the release of ChatGPT.

In this same snapshot with the older pages removed, signs of AI authorship were found in over one-third (35%) of the pages.

Drilling down into domains themselves, Pew found that URLs with a .com domain showed signs of AI authorship at around 10x the rate of a .edu or .gov domain (both of which were around 1% AI authored). In addition, .org domains had only a 4.6% rate of AI authorship.

Of course, this analysis is not perfect. Pangram, like other AI-detection tools, can misclassify pages as AI written when they weren’t. But at scale, the data is likely at least directionally correct.

In addition, Pew found that other supposed tells of AI authorship had also increased over the years, like the use of em dashes, Oxford commas, and phrasing like “it’s not X, it’s Y,” among other things.