AI Writing Assistant: Pick One by the Job, Not the Hype

The best AI writing assistant is the one built for the job you actually have. "Writing help" covers four different jobs, and the tools that are great at one are often clumsy at another. A grammar checker won't draft your proposal. A chat model will happily rewrite your whole email when you only wanted a typo fixed.

Here's the short version:

• Fix grammar, spelling and clarity: Grammarly, LanguageTool, ProWritingAid, or Hemingway Editor.
• Rewrite or paraphrase a sentence: QuillBot, Wordtune, or Grammarly's paid rewrites.
• Draft and edit inside the document you already use: Copilot in Word, Gemini in Google Docs, or Notion AI.
• Write long drafts from a brief or your notes: ChatGPT or Claude.

Most of these have a free version, and most of them do something with the text you paste in. Both details matter more than the feature list, so this guide covers them too.

Quick Comparison

The rest of this post goes job by job.

Proofreading and Grammar: The "Fix My Writing" Tools

If you mostly want an AI to fix your writing without changing what you meant, start here. These tools flag errors and suggest edits in place. You stay the writer.

Grammarly

Grammarly is the writing helper most people meet first, partly because it runs in the browser, on desktop and on mobile, so it checks text wherever you type. The company behind it now operates as Superhuman, and Grammarly's own site footer carries the Superhuman name.

According to Grammarly's plans page, the free plan covers spelling and grammar mistakes and shows your writing tone, with a monthly allowance of generative AI prompts. Pro adds full-sentence rewrites, unlimited personalized suggestions, and plagiarism and AI-text detection.

Best for: everyday writing across many apps, where you want light-touch corrections.

LanguageTool

LanguageTool is the pick if you write in more than one language, or if English isn't your first language and you want an English edit AI that also handles your other working languages. Its premium page says it comes in 30+ languages.

The free Basic plan caps how many characters it checks per text field and allows a few AI sentence rephrasings a day. Premium raises the character limit, unlocks enhanced grammar and style checks, and makes paraphrasing unlimited.

Best for: multilingual writers and non-native English speakers.

ProWritingAid

ProWritingAid goes deeper than a grammar checker. Its pricing page lists 25+ writing analysis reports on Premium, plus a custom style guide, and integrations with Microsoft Office and Google Docs. Fiction tools like Story Canvas and Chapter Critique show who it's built for: people writing books and long reports.

The free plan gives daily limits on line-editing reports and rephrases, and its FAQ says free users get suggestions for 500 words at a time.

Best for: novelists, long-form writers, and anyone who wants to understand their habits, not just fix them.

Hemingway Editor

Hemingway Editor does one thing: it makes your writing easier to read. The desktop app page says it highlights wordy sentences in yellow, worse ones in red, and flags adverbs, passive voice, and complicated words. That desktop version (now labelled Classic) is a one-time purchase and doesn't include the new AI features.

The AI version, Hemingway Editor Plus, fixes highlighted issues, checks grammar, and adjusts tone, with a free trial.

Best for: cutting a dense draft down to plain English.

Rewriting and Paraphrasing: When a Sentence Just Isn't Working

Grammar tools fix errors. Rewriting tools offer different ways to say the same thing. Use them when a sentence is correct but clunky.

QuillBot

QuillBot is built around its paraphraser: paste a sentence or paragraph, and it gives you a reworded version. If you're looking for a quick ai fix my writing tool that offers alternative phrasings, it's the obvious one to try.

The risk with any paraphraser is subtle meaning drift. Read every rewrite against your original before you accept it.

Wordtune

Wordtune, made by AI21 Labs, works at the sentence level. Select text and it suggests rewrites. Its plans page shows a free Basic plan with unlimited spelling and grammar checks, a daily cap on rewrites and AI suggestions, and a small monthly allowance of summaries.

Best for: quick alternatives for one sentence at a time, without leaving the page you're on.

Grammarly's paid plan also does full-sentence rewrites, so if you already pay for it, you may not need a separate paraphraser.

Drafting Inside Your Docs: Copilot, Gemini and Notion AI

These are AI text editors built into the place your document already lives. The big advantage is context: they can see the document, and sometimes your other files, without you copying anything across.

Copilot in Word

Microsoft's Copilot in Word guide splits it into three jobs: create a draft from a prompt, outline, notes or a referenced file; refine selected text by rewriting it, changing its tone or making it more concise; and summarize or answer questions about a document. It needs an eligible Microsoft 365 subscription or Microsoft Copilot license, and your organization can switch features off.

One naming note: Microsoft has renamed Microsoft 365 Copilot to Microsoft Copilot, so older guides use both names.

Gemini in Google Docs

Google's Docs help page describes editing with prompts across a section or the whole document, plus quick actions on selected text: rephrase, shorten, elaborate, bulletize, summarize, or make it more formal or casual. You can keep Gemini open in a side panel while you work. It requires an eligible Google Workspace or Google AI plan.

Notion AI

If your drafts start as notes, Notion AI can improve writing or generate drafts with AI blocks directly in your pages. The Free plan includes only a trial of Notion AI; Notion says it's included with the Business and Enterprise plans. If Notion is your main workspace, our comparison of Notion AI alternatives covers what else can see your notes.

Best for all three: people whose writing already lives in Word, Docs or Notion, and who don't want to copy and paste between tools.

Long-Form Drafting With a Chat Model: ChatGPT and Claude

For a first draft from a brief, a restructure of a messy document, or honest feedback on an argument, a general chat model is the most flexible writing assistant you can use. Claude's Free plan offers limited use with no payment required. Check OpenAI's site for ChatGPT's current plans.

They're also the easiest to misuse. A chat model rewrites everything unless you tell it not to. Three habits help:

1. Say what to keep. "Fix grammar and flow only. Don't change word choice or add sentences."
2. Ask for comments, not a rewrite. "List the five weakest sentences and explain why" teaches you more than a polished replacement.
3. Give it your examples. Paste two paragraphs you're proud of and ask it to match that style.

If you use Claude a lot, reusable skills can lock in those instructions so you don't retype them. Our guide to Claude skills for writing sorts them by job, and the copy editing skill is a good example of one that tightens what you already wrote instead of starting over. If your writing is mostly marketing copy at volume, see our Jasper AI alternatives instead; that's a different category of tool.

What Happens to Your Drafts: Privacy and Data Use

Every AI powered writing assistant sends your text somewhere to process it. The question is whether it's also kept or used to train models. Policies differ a lot, so check before you paste client work, contracts, or anything under NDA.

Sources: Superhuman's privacy policy, LanguageTool's privacy policy, Microsoft's Copilot privacy documentation, Google's Gemini Apps privacy hub, Notion's AI security practices, and Anthropic's model training article.

A few practical rules:

• Work and personal accounts are treated differently. Google says work or school accounts may be subject to different data handling terms, and Microsoft's commitments above are for its business product. Check which account you're signed into.
• Find the training setting once and decide. Grammarly, Gemini and Claude all give consumer users a setting. If you use ChatGPT, look for OpenAI's data controls too.
• Feedback buttons can change the rules. Anthropic says a thumbs up or down stores the whole related conversation. Google says feedback can be used for training even with Keep Activity off.

How to Keep Your Own Voice

The fastest way to sound like everyone else is to accept every suggestion. AI tools pull toward the average sentence, and the average sentence is forgettable. A few habits to enhance your writing without flattening it:

• Write the first draft yourself. Even a rough one. Editing your draft keeps your thinking; editing an AI draft keeps its thinking.
• Treat suggestions as questions. A flagged sentence means "look again," not "replace this."
• Keep a short list of words you never use. If the tool keeps adding them, reject them on sight.
• Read it out loud at the end. If a line sounds like a brochure, put your original back.
• Use readability tools last. Hemingway-style highlights are useful once the ideas are settled, not while you're still finding them.

This matters most for non-native speakers using English edit AI. Let the tool fix grammar, then check that the result still says what you meant, in words you'd actually use.

How to Choose

• You want free AI editing for everyday writing: start with Grammarly's or LanguageTool's free plan.
• You write in several languages: LanguageTool.
• You write books or long reports: ProWritingAid, with Hemingway for a final readability pass.
• You need a sentence said differently: Wordtune or QuillBot.
• Your work lives in Word, Docs or Notion: use the assistant already built in, if your plan includes it.
• You need a first draft or real feedback: ChatGPT or Claude, with clear instructions about what to keep.

Most people end up with two: one checker that runs everywhere, and one chat model for heavier lifts.

Where Taku Fits

A writing assistant helps with the words. The routine around them, like turning research notes into a brief, running the same edit pass on every newsletter, or applying a house style, usually lives in a pile of saved prompts. Taku is an AI-native desktop workspace where you can find an AI app, skill or workflow someone already built for that kind of job, mirror it into your own workspace, and remix it, without setting up repos or API keys. It sits alongside the tools above rather than replacing them. Taku is in Beta, and the Mac app is available now.

FAQ

What is the best AI writing assistant?

It depends on the job. For proofreading across apps, Grammarly or LanguageTool. For rewriting sentences, Wordtune or QuillBot. For drafting inside your documents, Copilot in Word or Gemini in Google Docs. For long drafts and feedback, ChatGPT or Claude.

Is there a free AI writing assistant?

Yes. Grammarly, LanguageTool, ProWritingAid and Wordtune all have free plans, and Claude has a limited-use Free plan. Free versions usually cap AI features, such as rewrites per day or characters per check, while basic spelling and grammar stay available.

Can AI fix my writing without changing my voice?

Yes, if you limit what it's allowed to change. Use a grammar checker rather than a rewriter, or tell a chat model to fix errors only and leave word choice alone. Then reread the result against your original.

Is there an AI word editor online for free?

Grammarly, LanguageTool and Wordtune all run in the browser on free plans. Gemini in Google Docs and Copilot in Word need an eligible Google or Microsoft plan.

What's the best English edit AI for non-native speakers?

LanguageTool is a strong choice if you also write in other languages. Grammarly is the most widely used for English alone. Either way, check that corrected sentences still say what you meant.

Is it safe to paste confidential work into an AI writing tool?

Only if you've checked how that tool handles your text. Some don't train on it by default, some let you opt out, and work accounts often have different terms from personal ones. When in doubt, use your company's approved tool or leave sensitive details out.