How Common Are AI Tells in Online Content?
Text across the web is picking up AI fingerprints. Pew Research Center analyzed 490,000 online pages: em dash use has roughly doubled since 2023, Oxford commas are up 63%, and phrasing like not just X but Y has nearly tripled. None of these tells alone prove AI authorship. Source: Statista
A new analysis from Pew Research Center is putting numbers on something many readers have already noticed: writing across the web increasingly carries the fingerprints of AI tools. Pew examined roughly 490,000 English-language online pages and tracked how often certain stylistic quirks associated with AI-generated text appear. Em dash usage has roughly doubled compared to 2023, the Oxford comma has risen 63 percent, and AI-associated vocabulary has more than doubled over the same period. Negative parallelism, the construction where a sentence frames something as not just one thing but also another, has nearly tripled since early 2023. Pew is careful to flag the limits of this kind of analysis. None of these individual tells, on their own, reliably proves that a specific piece of text was written by AI, since human writers use em dashes and Oxford commas too. AI detection tools built on these patterns still produce false positives when applied to single documents. The signal only becomes meaningful when looking at large volumes of text and tracking how usage has shifted since AI writing tools became widely available. Source: Pew Research Center via Statista.