For novelists, non-fiction writers and journalists
Manuscripts are being run through AI detectors now, sometimes without the author’s consent. See which passages would draw a flag, the stylistic reason behind each, and where an edit changed your voice. Nothing leaves your laptop.
500 words free · no account · your draft never leaves this device
Paste a chapter, or drop the manuscript. It is read here, on this device, and never uploaded.
Open the checker: 500 words free, nothing uploadedExample report
Illustrative example · invented text
A first-person narrator with a taste for dashes and threes. Invented for this page, then run through Ghost Act’s real pipeline; this is what it reported.
Calibrated ensemble
27% AI likelihood for the whole text. 6 passages marked, each with the reason.
What to take from itSix marks, and the verdict still leans human. The flags describe a voice: first person, fond of dashes, partial to threes. A bare percentage would show none of that; the reasons let you, or your agent, judge for yourselves.
The email from your agent
Three weeks before publication, your agent forwards an email without a word of her own. Someone has put chapter one through an online AI detector and posted a screenshot. It says your opening was probably written by a machine.
You wrote that chapter four times. You remember the morning the first line arrived. But the screenshot gives no reasons, and you cannot argue with a number that will not explain itself.
Ghost Act shows you the why: the dashes, the lists of three, the run of sentences that start with “I”, passage by passage, with an honest verdict. Print the report and send it back alongside your drafts and dated files, which are the evidence that matters most.
The problem
In 2026 a debut novelist’s unpublished manuscript was run through an AI detector without his consent, and his representatives dropped him after one phone call; he calls the flags cultural and points to his draft history. The same year the Commonwealth Short Story Prize spent a month reviewing drafts and timestamps before clearing winners accused on detector scores.
of human writing was wrongly labelled AI by OpenAI’s own classifier, which caught only 26% of AI text. OpenAI withdrew it within six months.
OpenAI (2023)of human texts with light, permitted AI editing were flagged by commercial detectors, against 9–15% of the same texts unedited.
Karr et al., arXiv (2026)of US adults want to be told about any AI contribution to a book; 61% would feel less fulfilled to learn one was AI-written.
YouGov (2025)of UK novelists say their work has been used to train AI without their permission, and 39% say they have already lost income to it.
Cambridge Univ. (2025)How Ghost Act helps
“I’m not uploading my manuscript anywhere”
The language model runs in your browser. Your manuscript is never uploaded, never stored on a server and never used to train anything. Saved reports live only in this browser.
“Why is my writing flagged?”
Em-dashes, lists of three, stacked transitions, repeated openers, over-used vocabulary: each flag says which habit it tripped. Often it is your voice, and now you can see where.
“Will my editor’s changes flag?”
The mixed-authorship check splits the text where the evidence shifts, so a paragraph smoothed by an editor or a grammar tool shows up on its own instead of colouring the whole book.
“Detectors hate fiction”
0% of 22 held-out book excerpts were wrongly flagged in validation, and we publish every genre’s rate, good and bad. When the evidence is borderline the verdict says “Uncertain” rather than guessing, and every flag shows its reason.
“Which box do I tick on KDP?”
Amazon KDP asks you to disclose AI-generated text, even if you edited it, but not AI-assisted work. Only you know how you worked; Ghost Act shows which passages read as generated, so you can look again first.
“My agent wants to know”
Print the full report for your agent, editor or publisher: the verdict, the reasons, the parts that read differently and the limits of the method. Context for a conversation, next to your drafts and dated files.
Compared
How Ghost Act differs from the detector a reader, journalist or competition might use.
| Feature | Ghost Act | Typical cloud detector |
|---|---|---|
| Where your manuscript goes | Stays in your browser: never uploaded, stored or used for training | Uploaded to the provider; retention and training use set by its terms |
| Why a passage was flagged | A plain-English reason on every flag | A percentage, sometimes highlights |
| Borderline text | An explicit “Uncertain” verdict | A number, however thin the evidence |
| False flags on fiction | 0% of 22 held-out book excerpts; every genre published | Rarely broken down by genre, so the rate on fiction is unknown |
| Edited passages | Mixed-authorship check shows where the voice changes | Usually one score for the whole document, edits included |
| Rewriting | Never. No “humaniser”, no paraphrasing | Some sell a rewriter to lower the score |
Paste text or drop a Word or PDF file. It is analysed in your browser and never leaves this device. The first 500 words are free.
“Leans human” and “Uncertain” are answers. See which passages drew a flag and why, and whether your style or an edit is behind it.
Save drafts, notes and version history as you go. If anyone asks, those show how you wrote; the printed report adds context.
Every figure on this page comes from Ghost Act’s published validation. How we measure
For writers
£39.99 a novelTry 500 words free, no account. A 100,000-word pack covers a full-length novel, and there is no subscription. Agencies and ghostwriting teams can use Pro at £100 a month.
Questions
No detector can prove authorship, including this one. The strongest evidence is your process: drafts, notes, research, dated files and version history. When the Commonwealth Short Story Prize reviewed accusations against its 2026 winners, it cleared them on working drafts and time-stamped documents. Ghost Act helps you understand how your prose reads and gives you a report to share alongside that evidence.
Detectors respond to patterns such as even sentence rhythm, stock transitions, lists of three, em-dashes and particular vocabulary, all of which people use too. Polished, formal or rhetorical prose, and some cultural and second-language styles, can read as machine-like. Ghost Act shows which of these it found and where, so you can see whether it is your style doing the talking.
They can nudge some detectors, because recent models use them heavily. Ghost Act treats em-dashes as a weak signal and says so in the report. Writers used dashes long before language models did; one habit on its own should never decide anything.
Sometimes. A 2026 study found that light, permitted AI editing was flagged by commercial detectors far more often than the same text unedited. Ghost Act’s mixed-authorship check shows which parts read differently from the rest, so you can see whether edits changed how a passage reads.
KDP asks you to disclose AI-generated content (text, images or translations created by an AI, even if you edited them substantially) and does not require disclosure of AI-assisted content, meaning work you created yourself and then edited, refined or checked with AI tools. Read KDP’s current guidance before you publish; Ghost Act cannot tell you which box to tick.
No. The analysis runs in your browser. Your manuscript is not uploaded, not stored on a server and never used for training. Saved reports live only in your browser on your device.
You can check it privately, but a low score does not make an entry eligible. Rules differ: some competitions disqualify AI-assisted work as well as AI-generated work, including translation by a language model. Read the rules, keep your drafts, and ask the organisers if you are unsure.
On held-out text it catches 81% of AI writing while wrongly flagging 3% of human writing, and it caught 82% of text from AI models it never saw during calibration. 0% of 22 held-out book excerpts were wrongly flagged. Scores from 29% up to the 78% flag threshold are reported as “Uncertain” rather than forced into a verdict. Full methods and every genre’s rate are on the methods page.
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