I’ve been testing a bunch of AI writing tools over the last year — mostly for long-form writing like novels, nonfiction books, guides, and self-published Kindle projects.

A lot of people ask: “Which AI tool is best for writing a full book?”

Truth is… it depends on your writing style.

Some tools are great for brainstorming, others for expanding chapters, and a few are actually usable for full book workflows.

Here’s a breakdown of 20 AI writing tools that are genuinely useful for writers.

No hype. No “this one tool can magically write your whole book.”
Just practical info.

📚 1. Aivolut Books

Best for: structured book creation
Perfect for people who want chapter frameworks, consistent tone, and a real book workflow (ideate → outline → draft → revise).

✍️ 2. WordHero

Best for: short-form + chapter expansion
Great templates and fast generation. Good for writers who outline in another tool then expand with WordHero.

📖 3. Sudowrite

Best for: fiction
Phenomenal at world-building, character emotions, and visual writing.

🧠 4. ChatGPT (Free or Paid)

Best for: brainstorming and editing
Not book-specific, but extremely flexible.

📘 5. Writesonic

Best for: nonfiction + blogs
Useful for writers making instructional or educational books.

⚡ 6. Claude.ai

Best for: polishing + rewriting
Very clean, coherent paragraphs. Great rewriting tool.

📝 7. NovelAI

Best for: fantasy and anime-style stories
Not ideal for nonfiction, but great for fiction inspiration.

📚 8. Jasper

Best for: marketing-heavy book writers
Strong SEO and content marketing angle.

📂 9. Notion AI

Best for: note-taking and book planning
Not a book generator, but great for organizing.

📄 10. Scrivener + any LLM

Best for: writers who want full control
Scrivener stays undefeated for long-form structure.

🪄 11. QuillBot

Best for: rewriting + clarity
Good for polishing chapters.

🌐 12. Google NotebookLM

Best for: nonfiction research
Amazing for summarizing and reorganizing sources.

💬 13. Rytr

Best for: quick drafts
Simple tool that works for fast idea generation.

📚 14. LibreOffice + local LLMs

Best for: totally free writing
Manual but powerful combo.

🎭 15. Character.AI

Best for: dialogue
Helps with conversations and character development.

✏️ 16. Ink for All

Best for: SEO book writers
Useful for keyword-based nonfiction.

📜 17. Hemingway Editor

Best for: simplifying writing
Great final editing tool.

✨ 18. Grammarly

Best for: grammar + clarity
Still essential for editing.

🔥 19. NovelCrafter

Best for: storyboarding fiction
Good for planning complex plots.

📘 20. Reedsy Book Editor

Best for: formatting
Not AI, but perfect for preparing your final manuscript.

So which one is “best”?

Depends on what you're writing:

For fiction:

• Sudowrite
• NovelAI
• Character.AI
• NovelCrafter

For nonfiction:

• Aivolut Books
• WordHero
• NotebookLM
• Writesonic

For editing:

• Claude
• Grammarly
• Hemingway

For idea generation:

• ChatGPT
• WordHero
• NotebookLM

There’s no one perfect tool — but combining 2–3 usually gives the best results.