I've already written about where I land on AI in publishing more broadly — genuinely useful as a tool, genuinely corrosive as a replacement for the writing itself. Editing and proofreading is where that distinction actually earns its keep, because it's the one place I use these tools on my own manuscripts, every single book.
The rule that makes this work: ask for a list of problems, never a rewrite. The moment you ask an AI tool to "improve this paragraph," you get back competent, grammatically flawless prose that sounds like nobody — not you, not any character, just the flattened average of everything the model has read. Ask it instead to find and report specific things, and it becomes a genuinely useful extra pair of eyes rather than a ghostwriter you didn't ask for.
Continuity checking. Paste in a chapter alongside your character or world reference notes, and prompt: "Read the chapter below against my character reference sheet, also below. List any inconsistencies you find — names, physical descriptions, dates, locations, or established facts that contradict the reference sheet. Quote the exact line for each one. Do not rewrite anything." This is the single highest-value use I've found, and it's exactly the kind of cross-referencing that's tedious to do by eye across a four-hundred-page manuscript but trivial for a model to hold in context at once.
Proofreading, narrowly. "Proofread the following passage for spelling, punctuation, and grammar errors only. List each one with the surrounding sentence and a one-line explanation of the error. Do not suggest stylistic rewrites, do not change my sentence structure, and do not flag anything that is a stylistic choice rather than an error." That last clause matters — without it, most tools will quietly start correcting sentence fragments and deliberate repetition that were authorial choices, not mistakes.
Crutch words and repetition. "Scan this chapter for words or phrases I use more than twice in close proximity, and words that appear overused across the whole excerpt. List each with a count and its locations. Do not rewrite or suggest alternatives." Every writer has verbal tics they're blind to — mine, after eighteen books, is still "quietly." A tool that can count is better at catching this than a human proofreader skimming for feel.
Timeline consistency. List out the implied day or date of each scene in a section, in order, and ask the tool to check whether the sequence is internally consistent and flag contradictions. This catches the kind of continuity error that comes from writing scenes out of order over months, which is almost every novel's actual drafting process.
One caution, in keeping with the concerns I raised about training data and consent: don't paste an entire unpublished manuscript into a free consumer AI tool without reading its data policy first. Look specifically for a stated no-training, no-retention clause, or use a paid tier where that's typically the default rather than the free one. It's a small discipline, but it's the same one I'd want other authors extending to my own books.
None of this replaces a real editor, and none of it replaces the four proper editing passes a manuscript actually needs. What it does is make the copyedit and proofread passes faster and more thorough before you either do them yourself or hand the manuscript to someone you're paying — which, done right, means you're paying for a shorter job.