Substack has introduced an AI-detection tool to help readers gauge whether posts, notes, comments and replies were written by artificial intelligence. Built on technology from detection firm Pangram, the feature aims to boost transparency on the platform as AI-generated content becomes more common on social media, addressing what chief executive Chris Best calls "Claudefishing" — when readers unwittingly invest attention in text with no human thought behind it.

The tool, announced in a blog post on Tuesday, is rolling out on the web and Substack's iOS app, with Android support due "soon". Readers can scan any post longer than 100 words via the "Scan for AI text" option in the three-dot menu, and writers can check their own drafts too, with the option to flag inaccurate results. Substack is also adding a "How I make this" statement so creators can explain their writing process, though Best acknowledges Pangram can only detect AI use, not the quality or human care behind a piece.