Pew Research Center ran nearly half a million webpages through an AI detector and found signs of AI authorship or editing on about 10%.
Among pages carrying a publication date after ChatGPT’s launch, the share was 35%.
Pew’s Data Labs team published their analysis on August 20, less than a year after two other major estimates of AI-generated text on the web.
What The Data Shows
Pages on .com domains tend to show signs of AI authorship at about 10 times the rate of pages on .edu and .gov domains. In a six-month average, the rate was 9.35% on .com, against 4.59% on .org, 1.03% on .edu, and 0.76% on .gov.
All four domain types sat at or below 1% in the sample collected before ChatGPT launched. They have separated since, with .com climbing fastest while .edu and .gov stayed close to the 1% mark.
The Tells Are Spreading
Pew examined specific markers in pages published after ChatGPT’s release. Em dashes increased from 5.79 uses per 10,000 words in early 2023 to 11.19 in early 2026. Oxford commas saw a 63% rise.
The use of words common to AI writing, such as “delve,” “interplay,” and “testament,” has more than doubled. The negative parallelism style, also known as the “it’s not just X, it’s Y” structure, increased from 0.87 to 2.36 uses per 10,000 words, though it still remains rare.
Pew says none of these traits can pin down a single document , since human writers use all of them. The claim is about rates across large sets of text.
I covered Ahrefs’ detector analysis in July, which ended with an open question about how useful a detector score really is as AI editing becomes more common in everyday writing tools. Pew’s data shows these markers appearing more frequently in their samples. Whether this makes any one marker more or less helpful for identifying AI is a different matter, and Pew didn’t explore that.
Other Estimates Disagree
Graphite, an SEO firm, estimated that the share of newly published English-language articles primarily AI-generated was 49.9% in the first quarter of 2026.
A preprint from Imperial College London, Internet Archive, and Stanford found that by mid-2025, 35% of newly published websites are detected as AI-generated or AI-assisted (not peer-reviewed).
All estimates lean on Pangram in some form, and Graphite also used Copyleaks and GPTZero.
The samples explain most of the gap. Pew scored every English-language page it collected, including forums, homepages, and category pages. Graphite restricted its sample to pages with article schema markup of at least 100 words that its classifier identified as an article or listicle. Forums and category pages are not where people reach for AI. Articles are.
Why This Matters
Signs of AI text are most prevalent on the commercial web. Pew’s .com detection percentage has climbed in every reading since ChatGPT launched, while .edu and .gov have stayed under 2%. Commercial pages are where the concentration sits, and that is the part of the web most SEO work touches.
Pew’s threshold catches AI editing too, so a page a person wrote and then cleaned up with a tool lands in the same category as one AI produced start to finish.
Looking Ahead
AI editing is now a native feature in Google Docs and Microsoft Word. Pew’s threshold already considers this type of writing, but none of the studies distinguish it from text entirely generated by AI.
Whether a page is accurate, useful, and worth publishing is still decided by reading it.
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