ChatGPT and Claude for Writers: Keep Your Voice, Edit Better, Follow the Rules

Use ChatGPT or Claude to draft, edit and keep your voice consistent. Which plan to pick, where to keep your style, prompts that work, and the rules on AI text.

Picks: 7; ranked

ChatGPT and Claude both work well for writing; the difference is in how you set them up. Keep your style notes and samples in a Project, so every chat starts in your voice, and use the assistant to edit and critique more than to write from scratch.

In ChatGPT, drafts now open in writing blocks, which replaced Canvas on current models in May 2026. In Claude, drafts open beside the chat and you can highlight a passage to change it in place. Plus and Pro both cost $20 a month. Whatever you use, AI-generated text must be disclosed on Amazon KDP, and prompts alone do not make a work copyrightable in the US.

Good for

Novelists and nonfiction authors who want a second reader for structure and line edits
Copywriters who need many on-brand versions of the same message
Journalists who use AI for transcripts, summaries and outlines, not published copy
Bloggers who draft and publish to WordPress
Self-published authors who need to follow Amazon KDP's AI rules

ChatGPT

Plan: Plus at $20 a month for most writers: 25 files per Project and 5,000-character custom instructions. Free works for trying it, with 5 files per Project.

What it can do

Draft and revise in writing blocks: edit text yourself, or select a passage and ask ChatGPT to revise it.
Write long pieces in a full-screen editor with a table of contents, then download them.
Keep your style guide, samples and chapters in a Project, with instructions that override your general custom instructions.
Add Google Drive, Box, Dropbox or SharePoint files from the Library.
Highlight text in any answer and choose Start writing to keep working on it.

Limits

Canvas is gone from GPT-5.5 Instant and Thinking; old guides that use its menus are out of date.
Custom GPTs retire on December 11, 2026, so do not build a new one for your voice.
On Free, Plus and Pro your chats can be used for training unless you turn off Improve the model for everyone in Settings > Data controls.
Google Drive files added to a Project do not stay in sync.

Plugs to turn on

Notion MCP: Pull research notes and outlines from Notion.
Canva MCP: Turn copy into social graphics.

Claude

Claude works as an editor and second reader here: keep the manuscript in a Project and change passages where they sit in the draft.

Plan: Pro at $20 a month, or $17 a month billed annually. Free gets up to 5 Projects to try it.

What it can do

Open drafts beside the chat; highlight a passage, type the change, and Claude edits it in place.
Keep a style guide, samples and chapters in Project knowledge so every chat in the Project uses them.
Build a voice skill from your own writing samples with Anthropic's Write in my voice guide.
Read and edit Google Docs through the Google Drive and Google Docs connectors, with your approval for each change.
Work across long manuscripts: paid Projects expand capacity up to 10 times.

Limits

Older guides mention a Styles menu; Anthropic's current help lists instructions, Project instructions and skills instead.
Chats on Free, Pro and Max are used for training only if Model Improvement is on; Incognito chats never are.
Google Drive files can be added only to private Projects, not shared ones.

Plugs to turn on

mcp-obsidian: Search and edit drafts in your Obsidian vault.
Zotero MCP: Cite sources from your Zotero library in nonfiction.

Gemini

Gemini fits writers who already draft in Google Docs, because it edits inside the document.

Plan: An eligible Google Workspace or Google AI plan for Gemini inside Google Docs.

What it can do

Rephrase, shorten, elaborate, summarize or change the tone of text inside Google Docs.
Match the style of another Google Drive document with Tools > Writing style.

Limits

Writing style matching is available to personal accounts only through Workspace Experiments.

Microsoft Copilot

Plan: An eligible Microsoft 365 subscription or a Microsoft Copilot license for Copilot in Word.

What it can do

Draft, rewrite selected text, change the tone and summarize inside Word.

Limits

Useful mainly if your manuscript already lives in Word.

Plugs to turn on

Microsoft Work IQ: Gives other assistants access to your Word files in OneDrive and SharePoint.

Plugs worth turning on

Official vendor servers first, then community servers by GitHub stars; only tools writers use for drafting, research, publishing or narration. Google Drive and Docs connectors are built into Claude and ChatGPT.

Keep your voice consistent with a ChatGPT Project

ChatGPT

1
Create a Project
In the ChatGPT sidebar, create a new Project for the book, client or publication.
2
Add instructions
Open the ••• menu, choose Project settings and write your instructions: audience, tone, words to avoid, sentence length. Project instructions override your general custom instructions.
Prompt
```
Write for busy small-business owners. Plain words, short sentences, no exclamation marks, no buzzwords. British spelling.
```
3
Upload your best samples
Add 3 to 5 pieces you are proud of and your style guide as Project files. Plus allows 25 files per Project, Free allows 5.
4
Draft in a writing block
Ask for the piece in the Project. It opens as a writing block, where you can edit it directly or select a passage and ask for a revision.
Prompt
```
Using the samples in this Project, draft a 600-word post about raising prices without losing customers. Match the tone of the samples, not a generic blog voice.
```
5
Give specific feedback
Ask for targeted changes rather than "make it better".
Prompt
```
Shorten this by 25% and make the final call to action clearer.
```

Get an editor's read of a chapter in Claude

Claude

1
Put the manuscript in a Project
Create a Project and add your chapters, outline and character or style notes to Project knowledge.

Ask for an editor's report, not a rewrite

Ask for problems and reasons first, so you keep the judgment and the voice.

Prompt

Act as an expert editor with several years of experience. Please provide a bullet point list of errors in spelling, punctuation, and grammar. Provide some general thoughts on style and structure.

3
Fix passages in place
Open the draft beside the chat, highlight a passage, type the change, and Claude edits it where you marked it.
4
Compare before you accept
Paste the old and new versions into a text-compare tool and keep only the changes you agree with. One author's rule: use AI for execution, not judgment.

Build a voice skill from your own writing in Claude

Claude

1
Collect samples
Export a folder of writing you are proud of: published pieces, sent emails, newsletters. Anthropic's guide also lets you point Claude at your sent mail instead.

Ask for a voice profile

In Cowork, point Claude at the folder and ask it to describe your voice with examples from the samples.

Prompt

Read the writing in this folder and describe my voice: sentence length, word choice, how I open and close, what I never do. Quote an example for each point.

3
Correct it
Tell Claude what it got wrong. The profile is only useful if it matches how you see your own writing.
4
Save it as a skill
Ask Claude to save the profile as a skill, such as /my-voice, and call it when you draft.
Prompt
```
Save this voice profile as a skill called my-voice.
```

Verdict

ChatGPT Plus and Claude Pro both cost $20 a month and both handle drafting and editing well. Set up a Project with your samples in each, test both on your own pages, and keep the one whose drafts you like.

Choose ChatGPT Plus or Claude Pro by trying both on the same chapter; either one is enough. The main limit is the same for both: they work best as an editor and second reader, and anything they generate still needs your judgment, your facts and, on KDP, a disclosure.

Best for

Editor's reports on chapters
Consistent voice across many pieces
Copy variants and headlines
Summaries and outlines from your research

Skip it if

You need publishable journalism without human sourcing
You want text you can copyright without your own expressive work
You cannot disclose AI-generated text where KDP or a publisher requires it

Questions

Is ChatGPT or Claude better for writing?

Neither wins outright. Both cost $20 a month for the paid plan and both edit well, so try both on the same chapter and keep the one whose drafts you like.

Can ChatGPT write a book?

It can draft one, but the result needs heavy work and has legal limits. In the US, text produced from prompts alone cannot be copyrighted, and Amazon KDP requires you to disclose AI-generated text.

Can I publish a book written with ChatGPT on Amazon KDP?

Yes, if you disclose it. KDP counts text an AI tool created as AI-generated even if you edited it heavily afterwards. Text you wrote and AI only edited or brainstormed does not need disclosure.

Can I copyright a book written with AI?

Only the parts where you made the expressive choices. The US Copyright Office says prompts alone are not enough, but your own writing and your arrangement or changes to AI text can be protected.

How do I make ChatGPT write in my voice?

Put your best samples and a short style guide in a Project, and write Project instructions on tone and words to avoid. OpenAI's own writing guide suggests turning a style you reuse into a skill.

Where did ChatGPT Canvas go?

OpenAI removed it from GPT-5.5 Instant and Thinking on May 28, 2026. Drafts now open in writing blocks, with a full-screen editor for long pieces.

Does ChatGPT or Claude train on my manuscript?

It can, on personal plans, unless you opt out. In ChatGPT turn off Improve the model for everyone under Settings > Data controls; in Claude turn off Model Improvement in privacy settings, or use an Incognito chat.

Can AI detectors tell if I used ChatGPT?

Not reliably. OpenAI shut down its own AI text classifier in July 2023 because of its low accuracy.

Is ChatGPT free for writing?

Yes, the Free plan writes and edits, with tighter limits and up to 5 files per Project. Plus costs $20 a month and allows 25 files per Project.

Can journalists use ChatGPT or Claude?

For research help, yes; for published copy, carefully. The AP tells staff to treat AI output as unvetted source material and not to use it to create publishable content.

Sources

Docs, issue trackers and discussions this page is built from.

Show all 27

help.openai.com · help.openai.com
help.openai.com · help.openai.com
support.claude.com · support.claude.com
help.openai.com · help.openai.com
claude.com · claude.com
kdp.amazon.com · kdp.amazon.com
www.copyright.gov · copyright.gov
help.openai.com · help.openai.com
help.openai.com · help.openai.com
help.openai.com · help.openai.com
help.openai.com · help.openai.com
support.claude.com · support.claude.com
support.claude.com · support.claude.com
Write in my voice · academy.claude.com
support.claude.com · support.claude.com
privacy.claude.com · privacy.claude.com
Gemini in Google Docs · support.google.com
Welcome to Copilot in Word · support.microsoft.com
WordPress.com MCP · developer.wordpress.com
github.com · github.com
github.com · github.com
openai.com · openai.com
How I use ChatGPT, The Common Reader · commonreader.co.uk
How I'm using AI and a real editor to refine my book · producingparadise.com
openai.com · openai.com
www.ap.org · ap.org
news.ycombinator.com · news.ycombinator.com