The best AI tools for writing emails
Most of us spend a surprising part of the week writing emails. AI can help you start a tricky message, make a reply friendlier or shorter, or catch a mistake before you hit send. The best tool depends on whether you want a writing assistant or a writing partner.
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Our top picks
Grammarly
Who it’s for: Anyone who wants spelling, grammar, clarity and tone suggestions directly in Gmail, Outlook and their browser, without copying and pasting.
Worth knowing: Some rewrites and advanced assistance are paid; keep your own voice.
ChatGPT
Who it’s for: People who want to describe a situation in plain English and get a full draft back, then refine it in conversation.
Worth knowing: Answers can sound confident and still be wrong. Check important facts.
Claude
Who it’s for: Anyone writing sensitive or important emails, such as complaints, apologies or job applications, who wants a calm, human-sounding draft.
Worth knowing: Free usage is limited; long sessions may need a paid plan.
Gemini
Who it’s for: People whose email already lives in Gmail. Paid Google AI plans bring Gemini into Gmail and Docs.
Worth knowing: Connected apps and model access depend on your account, region and plan.
QuillBot
Who it’s for: Anyone who has a draft that says the right thing but sounds awkward, and wants a few alternative phrasings (formal, simple, shorter) to choose from.
Worth knowing: Rewriting can change meaning. Review it and follow your school or work rules.
Visit QuillBot ↗ (affiliate link)
Side-by-side comparison
| Grammarly | ChatGPT | Claude | Gemini | QuillBot | |
|---|---|---|---|---|---|
| Best for | Polishing as you type | Drafting from scratch | Natural tone, important emails | Gmail users | Rewording your own sentences |
| Works inside your email | Yes, via apps and extensions | Copy and paste | Copy and paste (Outlook on paid plans) | Gmail on paid Google AI plans | Browser extension, or copy and paste |
| Free plan | Yes | Yes | Yes | Yes | Yes |
| Learning curve | Very easy | Very easy | Very easy | Very easy | Very easy |
Pricing
| Plan | Grammarly | ChatGPT | Claude | Gemini (Google AI) | QuillBot |
|---|---|---|---|---|---|
| Free | US$0 | US$0 | US$0 | US$0 | US$0 |
| Entry paid | Pro: US$12/month (as listed) | Go: US$8/month | Pro: US$20/month, or US$17/month billed annually | AI Plus: US$4.99/month (US listing) | Premium: AU$12.49/month billed annually (Australian listing) |
| Popular paid | Pro (as above) | Plus: US$20/month | Pro (as above) | AI Pro: US$19.99/month | Premium (as above) |
Prices checked on 14 October 2026 from official pricing pages (grammarly.com/plans, chatgpt.com/pricing with the OpenAI Help Center, claude.com/pricing, gemini.google/subscriptions and quillbot.com/premium (QuillBot shows local prices by region). Grammarly’s page didn’t state whether US$12 is the monthly or annual-billing rate, so check before you subscribe). Prices are in US dollars (USD) as listed. Australian prices, GST and app-store pricing can differ, and plans change often, so confirm on the provider’s site before you pay.
How to get started
Pick one tool to start. Grammarly if you want help as you type, ChatGPT or Claude if you want drafts.
For drafts, give context: who it’s to, what you need, the tone and a word limit. For example: “Write a polite, 100-word email to my landlord asking when the leaking tap will be fixed.”
Ask for changes in plain English: “shorter”, “warmer”, “less formal”, “make the request clearer”.
Read the final version yourself. Check names, dates, amounts and promises before you send.
How we chose
We focused on tools that are easy to start with, have a free plan, and genuinely save time on everyday email. We used each provider’s official pages and our own editorial judgement; we didn’t run a formal benchmark.
Assistant or partner?
There are two ways AI helps with email. A writing assistant like Grammarly sits inside your email and suggests improvements as you type: fixing a typo, flagging a confusing sentence or warning that a message might sound abrupt. You stay in control and keep your own voice. A writing partner like ChatGPT, Claude or Gemini writes a whole draft from your instructions. That’s brilliant for a blank page or a difficult message, but you’ll need to edit it so it sounds like you.
Many people use both: draft a tricky email with ChatGPT or Claude, then let Grammarly polish it in the email app. If you wrote the email yourself and one sentence just won’t come out right, a rephrasing tool like QuillBot gives you several versions to pick from. Not sure whether you need a checker or a rephraser? See Grammarly vs QuillBot. If you’re unsure which chat assistant to try, read our ChatGPT vs Claude vs Gemini comparison.
Tips for better AI emails
- Give the facts, not just the goal. AI can’t know your dates, prices or history unless you tell it, and it may invent details if you don’t.
- Set the tone and length. “Friendly but firm, under 120 words” works far better than “write an email”.
- Keep it personal. Add a line only you would write. Recipients can often tell when a message is entirely AI-generated.
What to watch out for
Avoid pasting confidential information, passwords or other people’s personal details into AI tools, and check your workplace’s rules on AI use. Review every email before sending. You’re responsible for what it says, not the AI.
Example prompts to try
Copy one of these into ChatGPT, Claude or Gemini and replace the details in brackets:
- “Write a short, friendly email to [name] asking to move our meeting from [day] to [day]. Keep it under 80 words.”
- “Rewrite this email so it’s polite but firm. Don’t add any new facts: [paste your draft].”
- “Turn these dot points into a clear email to my team, with a one-line summary at the top: [points].”
- “Suggest three subject lines for this email: [paste email].”
With Grammarly, you don’t need prompts: just write in your email app and accept or ignore its suggestions. Its tone detector is handy before sending something emotional.
Our verdict
For everyday email, Grammarly’s free plan is the lowest-effort upgrade because it works where you already write. Add ChatGPT or Claude for blank-page moments and difficult messages. Gmail users on a paid Google AI plan can do much of this directly in their inbox with Gemini.
Frequently asked questions
What is the best free AI tool for writing emails?
Grammarly’s free plan is great for checking spelling, grammar and clarity as you type. For drafting full emails for free, ChatGPT, Claude and Gemini all have free plans.
Can AI write emails for me in Gmail or Outlook?
Grammarly works inside Gmail and Outlook through its apps and browser extension. Gemini is built into Gmail on paid Google AI plans, and Claude’s paid plans include Microsoft 365 and Outlook features. Otherwise you can copy and paste a draft.
How much does Grammarly Pro cost?
Grammarly’s plans page listed Pro at US$12 a month when we checked on 14 October 2026, with a 7-day free trial. Check whether that rate requires annual billing.
Will people know my email was written by AI?
Sometimes. AI drafts can sound generic. Give clear context, edit the draft into your own words and add a personal detail.
Is it safe to use AI for work emails?
It depends on your workplace’s policy and the information involved. Avoid pasting confidential or personal information, and check your organisation’s rules on approved AI tools.