Best AI for writing in 2026: the tool we’d use for each job

There isn’t one best AI for writing, because a novel, a board report and a cover letter need different help. So we’ve sorted nine tools by the job each does best: Claude, ChatGPT, Gemini, Microsoft Copilot in Word, Grammarly, QuillBot, Sudowrite, ProWritingAid and Notion AI. Prices, plans and features come from each vendor’s own pages, checked on 30 September 2026. We describe what each tool is built and documented to do. We haven’t run a scored writing test for this guide.

All nine side by side

Prices are US list prices for one person, as the vendors showed them on 30 September 2026. ProWritingAid would only show us euro prices from Ireland, so those are in euros.

Tool	Best for	Free plan	Paid from	Where it works
ClaudeAnthropic · claude.ai	Long drafts, editing	Yes, Sonnet 5.5	$20 / month ($17 annual)	Web, desktop, mobile; Word on paid plans
ChatGPTOpenAI · chatgpt.com	All-rounder, free in Word	Yes, GPT-5.6 Luna	$8 (Go), $20 (Plus)	Web, apps; Word add-in on every plan
GeminiGoogle · gemini.google	Google Docs and Gmail	Yes, Flash-Lite	$4.99 (AI Plus), $19.99 (AI Pro)	Gemini app; Docs from AI Pro
Copilot in WordMicrosoft 365	Word and Outlook	Copilot chat, lower usage	$9.99 / month (Personal)	Word, Excel, PowerPoint, Outlook, OneNote
Grammarlygrammarly.com	Grammar and tone	Yes, 100 AI prompts a month	$12 / month billed yearly	Browsers, Windows, Mac, Office, Google Docs, mobile
QuillBotquillbot.com	Paraphrasing	Yes, with limits	$99.95 / year or $19.95 / month	Web, Chrome, Word
Sudowritesudowrite.com	Fiction	Free trial	$10 / month billed yearly	Its own writing app
ProWritingAidprowritingaid.com	Manuscript editing	Yes, 500 words per report	€10 / month billed yearly	Web, desktop, Google Docs, Office
Notion AInotion.com	Notes and team docs	Limited trial	$20 / member / month (Business, yearly)	Inside Notion

Long drafts and heavy editing

For anything longer than a page, you want a general assistant that can hold the whole document in view and take instructions about style. Two are worth paying for here, and both have usable free plans.

Claude

Claude is where we’d start a long piece. Anthropic’s two newest models both came out this month and both were sold partly on how they write. Of Opus 5.5 (22 September), Anthropic says it “puts the most important information up front, is less likely to use jargon or idiosyncratic phrases, and follows the writing rules you give it”. Sonnet 5.5 followed on 28 September, and Anthropic’s page says its “writing is clearer and more direct, so drafts need less cleanup”. Those are vendor claims. Still, a model that sticks to your style guide is exactly what you want when editing.

Sonnet 5.5 is on the Free plan, too. Anthropic says “anyone can chat with Claude using Sonnet 5.5” on the web, iOS and Android. Pro adds Opus, Projects without the five-project cap, Claude Design with Slides and Docs, and Claude for Microsoft 365. In Word that add-in edits “with tracked changes”, replies to comment threads and follows company styles. If you’re not sure you need the bigger model, our guide to Sonnet or Opus covers when the cheaper one is enough.

ChatGPT

ChatGPT covers more ground as an everyday app. For writers, the most useful recent addition is ChatGPT for Word, which OpenAI offers on every plan, Free included. Free and Go use GPT-5.6 Luna inside Word; Plus and Pro default to GPT-5.6 Sol. OpenAI’s newest model, GPT-6.1 Sol, arrived on 29 September, but for now only in ChatGPT Work and Codex. OpenAI says it “is not yet available in Chat”. If you’re deciding between Claude and ChatGPT for more than writing, our Claude vs ChatGPT comparison goes through plans, context and privacy.

Work email and documents in Word or Google Docs

For reports, briefs and email, the best AI is usually the one already built into the software you use at work, because it can see the file you’re in. Copying and pasting into a chat window works, but you lose formatting and comments on the way back.

Microsoft Copilot in Word

If you live in Word and Outlook, this is the obvious pick. Microsoft’s support page lists four jobs: start a draft “from a prompt, outline, notes, or referenced file”, rewrite selected text or “adjust tone”, summarise a document, and make “reviewable changes” in the original file. For home users it comes with Microsoft 365 Personal at $9.99 a month or $99.99 a year. Family costs $12.99, but only the subscription owner gets the AI features. Premium at $19.99 raises Copilot use from “higher usage than free” to “extensive usage”. Work accounts need Microsoft 365 Copilot, which Microsoft sells as an add-on to its business plans.

Gemini in Google Docs

Google’s version can pull from your Drive, Gmail and Chat to build a full draft, then use Match Format and Match Writing Style to bring it in line with your house style and tone. On a personal Google account, Docs is listed from Google AI Pro at $19.99 a month. The $4.99 AI Plus plan lists “Gemini in Gmail, Vids, and more” but not Docs, so check before you buy it for this. The Gemini app itself is free with the Flash-Lite model, Canvas and Deep Research. We set Google AI Pro against Claude Pro and ChatGPT Plus in a separate guide.

Notion AI

If your team writes in Notion, its built-in agent can chat, generate and edit docs, and translate inside the workspace. On the Free and Plus plans, though, it’s only a limited trial. The full version comes with Business at $20 per member a month on yearly billing, or $24 monthly. That’s a lot to pay for writing help alone, so it only makes sense if you also want the meeting notes and search that come with Business.

Grammar and style checking

A chatbot will proofread if you ask, but a checker marks problems as you type, in the app you’re typing in. Grammarly is the one we’d install first. The free version corrects spelling and grammar, shows your tone and gives you 100 AI prompts a month. Pro adds one-click rewrites of whole sentences, tone adjustment, a plagiarism check and 2,000 prompts. It costs $12 a month billed yearly ($144), or $30 if you pay monthly, so the annual plan is much the better deal.

Fiction

General chatbots can write a scene, but they don’t know your book. Sudowrite does, and it’s the tool we’d point a novelist to. It gives you Write, Rewrite, Describe and Expand, matches your style and checks continuity across a series. It runs Sudowrite’s own fiction models, Muse and Ballad, alongside more than 30 others. Plans are sold as monthly credits. Hobby & Student is $10 a month billed yearly ($19 monthly) for 225,000, Professional $22 ($29) for 1,000,000, and Max $44 ($59) for 2,000,000. Feedback, meaning developmental edits, line edits and beta reads, is only on Professional and Max. There’s a free trial with no card needed.

ProWritingAid is the better choice when the draft already exists and you want it edited. It runs line-editing reports on readability, overused words and sensory detail, and offers chapter critiques and paid manuscript analysis. The free plan allows two runs of each report a day on 500 words, plus ten rephrases. Premium was €10 a month billed yearly (€120) or €30 monthly when we looked from Ireland, and there’s a lifetime licence from €399. If the finished book is headed for audio, we compare AI narration tools for audiobooks separately.

Rewriting and paraphrasing

QuillBot is best known for its paraphraser, which rewrites a sentence or paragraph in a different tone or length. The paraphraser and grammar checker are free with limited access, while the citation generator, translator and AI detector are free outright. Premium opens up all of the tools and costs $99.95 a year, which works out at $8.33 a month, or $19.95 if you pay monthly. It works on the web, in Chrome and in Word.

Paraphrasers are also sold as a way to get text past AI detectors, and QuillBot sells both a humaniser and a detector. We’d leave that game alone. AI detectors get it wrong often enough, on human writing as well as machine text, that a score proves nothing either way. If your school or client has rules about AI use, the safe course is to follow them and say what you used.

The best free setup

You can do a lot without paying. Claude Free with Sonnet 5.5 is the free option we’d use for drafting and editing, because it’s Anthropic’s newest model and the one it describes as writing more clearly. Add Grammarly Free for proofreading wherever you type. If you need AI inside Word without a Microsoft 365 subscription, ChatGPT’s Word add-in works on the Free plan. Gemini’s free app is the one to add if your files already live in Google Drive.

Frequently asked questions

Sources and method