More than one-third of newer webpages show signs of AI authorship

More than one-third of webpages published after ChatGPT’s release show signs of being written or substantially edited by artificial intelligence, according to a Pew Research study.

Pew used the Common Crawl web archive to collect nearly half a million English-language webpages from about the past five years. It used Open Pangram’s detection technology to estimate how many were likely written or heavily edited by AI.

In a random sample of 10,000 webpages collected in July 2026, about 10% showed significant signs of AI authorship. After Pew removed pages published before ChatGPT’s November 2022 release, the share rose to 35%.

The study found signs of AI authorship on .com domains at about 10 times the rate of .edu and .gov domains, where the rate was about 1%. The rate for .org domains was 4.6%.

Pew cautioned that AI-detection tools can misclassify pages, but said the results were directionally useful at scale. The study also found increased use of patterns such as em dashes, Oxford commas and “it’s not X, it’s Y” phrasing.