Are AI Detectors Accurate? What the Research Says

AI detectors promise to tell you whether a person or a chatbot wrote something, often with a confident percentage. The reality is messier. Here's what the evidence shows.

How AI detectors work

Most detectors don't look for watermarks. They measure how predictable the text is: how expected each next word is (often called perplexity) and how much sentence length and structure vary ("burstiness"). AI text tends to be very predictable and evenly paced, so low scores on both suggest AI. The problem is that plenty of human writing is predictable too.

What the evidence says

• OpenAI withdrew its own detector. In 2023 OpenAI shut down its AI text classifier, citing its low rate of accuracy.
• Non-native writers get flagged more. A 2023 Stanford study (Liang et al.) found that popular detectors labelled a large share of essays by non-native English speakers as AI-written, while doing far better on essays by native speakers. Simpler vocabulary and grammar look "predictable".
• Tool makers admit false positives. Turnitin, widely used in schools, says its AI indicator can produce false positives and shouldn't be used as the sole basis for action against a student.
• Light editing changes results. Paraphrasing or rewriting AI text often changes a detector's verdict completely, which shows how much it depends on surface patterns.

Why human writing gets flagged

• Formal or formulaic writing: lab reports, legal text, cover letters.
• Short texts, which give the detector very little to go on.
• Writing by non-native speakers, or text polished with grammar tools.
• Common topics where everyone uses the same phrases.

If you've been flagged unfairly

1. Ask what the decision is based on. A detector score alone isn't proof, and most tool makers say so.
2. Show your process: drafts, version history in Google Docs or Word, notes and sources.
3. Offer to explain the work in person. Knowing your own material is the strongest evidence.

Writing that reads as yours

The best protection is writing that genuinely sounds like you: varied sentences, your own word choices, specific details and opinions. If you start from an AI draft, rewrite it in your voice rather than just swapping synonyms. That's what GhostVerb's "Your voice" style is built to do. It keeps your rhythm, spelling and tone and drops the usual AI words.

No honest tool can guarantee a detector result, because the detectors themselves aren't consistent. Natural writing is the goal, not gaming a score. Always follow your school's or employer's rules on AI use.