How does AI content detection work?
A detector is a classifier trained on examples of human and machine output. For text, many lean on how predictable the wording is to a language model: smooth, common phrasing scores as machine-like, while unusual word choices score as human. The detector judges style, not authorship, which is why a careful human writer with a plain style can fail it and a model prompted to write unevenly can pass.
How accurate are AI detectors?
Less accurate than their marketing implies, and wrong in a biased direction. A Stanford study ran seven detectors on essays written by non-native English speakers and found an average false positive rate of 61.22%; when the same essays were polished with ChatGPT for richer vocabulary, the rate fell to 11.77% (Liang et al., arXiv, read 2 November 2026). The tools punished plain human writing, and editing with AI made it pass. A false positive accuses a real person, so in hiring, grading or supplier disputes the cost of a wrong flag lands on someone who did nothing wrong.
What is the best AI detection tool?
The one you never use alone. Ask for the false positive rate on content like yours, not a headline accuracy figure; prefer tools that show which passages drove the score; and route every flag to a person who can ask the author for drafts or sources. Write the rule into your AI usage policy: no consequential decision rests on a detector score by itself. If the real worry is low-effort output inside your own company, that is an AI slop review problem, not a detection one.
Why are watermarking and provenance the sturdier route?
Because they record origin at creation instead of guessing it afterward.
| Method | What it checks | Needs the generator to cooperate | What it can establish |
|---|---|---|---|
| Detection | Statistical style of finished content | No | A likelihood, with false positives |
| AI watermarking | A hidden signal added during generation | Yes | Likely machine origin, weakened by heavy editing |
| C2PA credentials | A signed record of creation and edits | Yes | Recorded history, if the manifest survives |
For media your company produces, sign it; for media you receive, ask for credentials before you run a detector. Content provenance gives positive evidence where it exists, while missing credentials or a missing watermark still prove nothing about human authorship.