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The best AI for writing, by the kind of writing you do
Writing quality is hard to score, and we haven’t found a current independent writing test we can cite, so the best choice depends on the job. Everyday emails and posts work fine on any free chatbot. For writing inside your documents, Gemini and Copilot come with Google’s and Microsoft’s plans. Grammarly polishes what you wrote, and Sudowrite is built for fiction. Here is what each does and costs.
Checked October 18, 2026 against each company’s own plans and pricing pages
| Job | Tool | Free | Paid, a month |
|---|---|---|---|
| Emails, posts, drafts | ChatGPT, Claude or Gemini | Yes, all three | About $20 for more use and stronger models |
| Writing in Google Docs | Gemini in Docs | No | Google AI Pro $19.99; Workspace Business Standard $14 a user |
| Writing in Word | Copilot in Word | No | Microsoft 365 Personal $9.99; Premium $19.99 for extensive use |
| Word, PowerPoint and Sheets, with ChatGPT | ChatGPT’s extensions for Word, PowerPoint, Excel and Google Sheets | Limited, on Free and Go | ChatGPT Plus $20 |
| Spelling, grammar and tone | Grammarly | Yes, with 100 AI prompts | Pro $12 |
| Novels and screenplays | Sudowrite | Free trial | $10, $22 or $44; up to 50% off yearly |
Everyday writing: the free chatbots
For emails, social posts, cover letters and first drafts, the free plans of ChatGPT, Claude and Gemini are enough. ChatGPT’s free plan allows unlimited text chats; Claude’s free plan uses Anthropic’s Sonnet model, which scores higher on independent capability tests than the other free models (see the best AI chatbots). Paste in an example of your own writing and ask it to match the tone.
Anthropic says its newest models write more plainly. It describes Claude Opus 5.5, included with Claude Pro, as putting the most important information first, avoiding jargon and following the writing rules you give it (Anthropic).
Writing inside your documents
Google Docs: Gemini drafts and polishes text in Docs with Google AI Pro ($19.99 a month), or for teams with Google Workspace Business Standard ($14 a user a month with a one-year commitment). Word: Microsoft 365 Personal ($9.99 a month) puts Copilot in Word, Excel, PowerPoint and Outlook, with Premium ($19.99) for extensive use. ChatGPT adds extensions for Word, PowerPoint, Excel and Google Sheets on Plus and Pro; Free and Go get limited use. See the best AI for business for team plans.
Editing what you wrote: Grammarly
Grammarly’s free plan catches spelling and grammar mistakes, shows your tone and includes 100 AI prompts to generate text. Pro costs $12 a month, with a free trial.
Fiction: Sudowrite
Sudowrite is built for fiction writers. Hobby & Student costs $10 a month for 225,000 credits; Professional, at $22, is aimed at longer works such as a novel or screenplay; Max, at $44, has 2,000,000 credits that roll over for 12 months. Each has a free trial with no card, and paying yearly saves up to 50%.
Through an API, the words themselves are cheap: a 90,000-word draft is about 120,000 tokens of output, which costs about $1.20 on Claude Sonnet 5.5, $2.40 on Claude Opus 5.5 and $6.00 on GPT-6 Astra. Planning, rewrites and long context to keep the story straight add more.
What writers say
- Style is the main complaint. In the Claude Opus 5.5 launch discussion, some commenters said the wordy style of earlier Claude models had sent them to other tools, and hoped the clearer writing would last.
- Denser isn’t shorter. At the Fable 5.1 launch, an Anthropic employee called its writing a big step up, while one user pointed out that dense prose is not the same as concise prose.
- Give it your rules. Anthropic says Opus 5.5 follows the writing rules you give it; a sample of your own writing helps any model match your voice.
Questions
What is the best AI for writing?
For everyday writing, the free plan of ChatGPT, Claude or Gemini. For writing inside documents, Gemini in Google Docs or Copilot in Word. For polishing, Grammarly; for fiction, Sudowrite.
What is the best free AI for writing?
ChatGPT’s free plan for unlimited text chats, Claude’s free plan for its stronger Sonnet model, and Grammarly’s free plan for spelling, grammar and tone.
Can I use AI to write essays for school?
Check your school’s rules first; many set their own. AI is most useful for planning, feedback on a draft and explanations. See the best AI for studying.
Sources
- ChatGPT pricing, Claude plans and Gemini subscriptions
- Google Workspace pricing and Microsoft 365 plans with Copilot
- Grammarly plans and Sudowrite pricing
- Anthropic: Claude Opus 5.5 (writing claims) and the Hacker News discussions linked above