Substack adds AI-detection tool to flag AI-written newsletters

Substack this week announced an integration with Pangram, AI writing-detection software, that lets users scan posts, comments, and replies inside Substack’s app and see an estimate of how much of that content was written by a human and how much was generated by AI. The feature will be available for any post, note, reply, or comment above 100 characters.

In the short term, the move might be bad for Substack’s business: it could expose newsletters on the platform that aren’t entirely written by people, which could potentially erode trust in the platform’s ecosystem of independent news and blogs, or even damage its reputation as a host of high-quality content. In the long term, though, AI-detection features could help keep Substack free of “AI slop” and encourage more users to trust that what they’re reading was written by a person, or at least better understand when it’s not.

The move places Substack among a growing group of platforms leaning toward labeling AI-generated content, now that AI is playing a greater role in content creation generally. Social media platforms already label AI-generated photos and videos, and music-streaming services have more recently started labeling, and in some cases penalizing, AI-generated music.

Substack CEO Chris Best called the integration a good use of AI. In an online chat with Pangram founder Max Spero, Best recounted the pitch he used to make to writers considering the platform: “When I used to pitch Substack to writers, one way I would do it is … we’ll do everything for you except the hard part,” he said, adding, “You have to have something — an idea that’s worth reading, that’s worth caring about, that’s worth sharing. That one thing is very hard and very valuable … [S]oftware should do everything else, but I think you do want the person to do the hard part.”

Substack will also let writers attach an optional AI author’s note so creators can properly disclose their use of AI, the company told TechCrunch. Substack clarified that the tool isn’t meant to prohibit or penalize AI-assisted writing; rather, it’s meant to encourage writers to add a “how I make this” statement explaining their process, and it will let publishers run Pangram on their own drafts before publication and flag scans of their own work they believe are mistaken.

Why it matters

As AI writing tools become more embedded in content creation, platforms that host independent publishers face pressure to help readers tell human from machine authorship without banning AI assistance outright. Substack’s bet is that transparency, not prohibition, is what preserves reader trust.