Guide to AI writing tools
Best AI for Writing a Book: ChatGPT, Claude, Sudowrite and More
Seven AI writing tools compared on price and what each does best, plus how to write a book with ChatGPT and the rules for publishing it.
The best AI for writing a book depends on the job. For drafting fiction, Sudowrite and Novelcrafter are built around scenes and story notes. For brainstorming, outlining and feedback, ChatGPT and Claude do well and have free plans. Whichever you use, outline first, keep a sheet of story facts, and revise every chapter in your own voice.
Below, seven tools are compared on price and fit, with every price read from the maker's own page on October 6, 2026. After the table come Sudowrite's prices and its closest alternatives, a method for writing a book with ChatGPT without losing the thread, and the rules for publishing a book that AI helped write. Looking for writing apps without AI, such as Scrivener? See the best book writing software.
The best AI tools for writing a book, compared
General assistants handle any kind of writing and have free plans. Fiction tools cost more but are built around scenes, beats and story notes. You can also use one of each: a chat assistant to think out loud and a fiction tool to draft.
AI tools for writing a book, by what each does best
| Tool | Best for | Price a month |
|---|---|---|
| ChatGPT | Brainstorming, outlines and quick drafts of almost anything | Free; Go $8; Plus $20; Pro from $100 |
| Claude | Talking through a long draft, feedback and rewrites | Free; Pro $20, or $17 billed yearly; Max from $100 |
| Sudowrite | Drafting fiction with tools and models made for novelists | Free trial; $10, $22 or $44 billed yearly, or $19, $29 or $59 monthly |
| Novelcrafter | Planners who want detailed story notes and their own choice of AI model | 21-day trial; $4 to $20, plus what your AI provider charges |
| NovelAI | Co-writing fiction turn by turn, with unlimited text on paid plans | 50 free generations; $10, $15 or $25 |
| Squibler | Generating a full-length first draft from your idea | Free plan; Plus $29.99, or $15.83 billed yearly; Pro $89.99, or $49.17 billed yearly |
| River | A free tool for each step, from outline to chapter to edit, saved as documents | Free plan, no card; $14, $36 or $100 |
Prices in US dollars from each maker's pricing page, checked October 6, 2026. Prices change, so check before you buy.
Which AI should you use for each step?
- Brainstorm and outline: ChatGPT or Claude. Both have free plans, and either can turn a premise into a chapter plan you can push back on.
- Draft fiction: Sudowrite or Novelcrafter, or River's chapter writer, which turns your beats into a scene in your voice. To start a novel from one sentence, the AI novel writer gives you a chapter plan and chapter one.
- Keep a long book consistent: Novelcrafter's Codex, or a story bible built from your chapters that lists every name, place and rule.
- Get a whole first draft fast: Squibler is built to generate a full-length manuscript from your idea. Set aside time to rewrite it in your own voice.
- Write nonfiction or a memoir: a general assistant, or the AI book writer, which builds a chapter plan and a full first chapter from your idea or notes.
- Revise: the story rewriter changes a passage the way you choose, such as point of view or tense, and the plot hole finder checks a whole draft for contradictions.
Sudowrite pricing and the best Sudowrite alternatives
Sudowrite's pricing page shows yearly prices first: Hobby & Student, Professional and Max cost $10, $22 and $44 a month, billed annually. Switch the toggle to monthly and they cost $19, $29 and $59. Every plan includes the drafting tools and Sudowrite's Muse fiction model, but Feedback, its developmental edit, line edit and beta read tool, needs Professional or Max. Monthly credits run from 225,000 to 2,000,000, and Max rolls unused credits over for 12 months. There's a free trial with no card, but no free plan.
If the price or the credits don't suit you, these are the closest alternatives as of October 6, 2026.
- Novelcrafter: $4 to $20 a month, with AI features from the $8 Hobbyist plan. Novelcrafter has no AI of its own, so you connect a provider such as OpenRouter and pay it for what you use, or run a model on your own computer (Novelcrafter's AI FAQ).
- NovelAI: a flat $10, $15 or $25 a month with unlimited text generation, made for writing a story with the AI one turn at a time.
- ChatGPT or Claude: free plans, then from $8 a month for ChatGPT Go or $20 for Claude Pro. Neither has scene or story bible tools, so you bring the structure.
- River: a free plan with no card, then $14, $36 or $100 a month, with separate free tools to draft a chapter, rewrite a passage or edit a manuscript.
Novelcrafter vs Sudowrite
| Feature | Novelcrafter | Sudowrite |
|---|---|---|
| Price a month | $4, $8, $14 or $20; two months off when you pay yearly | $19, $29 or $59; $10, $22 or $44 billed yearly |
| Try it | 21-day free trial, no card | Free trial, no card |
| AI | Bring your own from the $8 plan up: a provider you pay, or a model on your computer | Included as monthly credits, with its own Muse and Ballad fiction models |
| Story notes | The Codex: characters, locations and more, tracked as the story changes | A Story Bible that its drafting tools read from |
| Export | Word or Markdown, with the Codex if you choose | Word, one document or a whole project; Story Bible sections as spreadsheets |
| Best for | Planners who want control of the model and the cost | Writers who want AI ready to use on day one |
From each tool's pricing and help pages, checked October 6, 2026. Export guides for both are linked at the end of this page.
How to write a book with ChatGPT
ChatGPT can write a book, but only a piece at a time, and you have to hold the plan. These steps keep a long project on track in any chat assistant, Claude included.
Settle the plan first
Ask for a one-page premise and a chapter-by-chapter outline before any prose. Change the plan now, while it costs nothing.
Keep a facts sheet
In a document of your own, list names, ages, places, rules and what each chapter changed. Update it after every chapter.
Use one chat per chapter
Open each new chat with the facts sheet, that chapter's line from the outline and the last page of the chapter before.
Draft from beats
List the four to six things that happen in the chapter, and paste a page of your own prose so it can match your voice.
Save as you go
Copy each finished chapter into one manuscript file. A book that lives only in chat history is hard to find and harder to revise.
Revise in your own voice
Read each chapter aloud, cut stock phrases, and check it against the facts sheet before you move on.
Why long chats lose the thread
ChatGPT only keeps part of a long conversation in view, so earlier chapters drop out of a long chat. Paste your facts sheet into each new chat rather than trusting it to remember.
Prefer to skip the juggling? The AI book writer turns an idea or notes into a chapter plan and a full first chapter in one document, and continue my story picks up from your last line in your voice.
Will the AI train on your book?
It depends on the tool and your settings. On personal plans, ChatGPT can use your chats to improve its models unless you switch off "Improve the model for everyone" in Settings, under Data Controls (OpenAI's data controls FAQ). Sudowrite's pricing page says it doesn't use your writing to train its own or OpenAI's models. With Novelcrafter, the policy of whichever AI provider you connect applies. River's privacy policy says it doesn't train AI models on your documents.
Publishing a book written with AI
Amazon asks you to tell it about AI-generated text, images or translations when you publish through KDP, but not about AI-assisted work such as editing text you wrote yourself (KDP content guidelines).
Copyright is the other question. The US Copyright Office's report on AI and copyrightability says copyright protects what a person wrote or meaningfully shaped, not text an AI produced on its own, and that prompts alone aren't enough. If a publisher registers the copyright for you, the Authors Guild advises telling them which parts AI generated.