Best AI for writing emails
What is the best AI for writing emails?
Claude is the best AI for writing emails if tone matters, because its drafts sound natural and it softens or firms up wording well. Microsoft Copilot is best if you live in Outlook, Gemini suits Gmail users, and ChatGPT is a strong free all-rounder. All four have free plans that can draft an email from a few notes.
Our shortlist
| # | Tool | Best for | Free plan? | Paid from |
|---|---|---|---|---|
| 1 | Claude | Best for getting the tone right | Yes | US$20/month (Pro), or US$17/month billed annually |
| 2 | Microsoft Copilot | Best for Outlook users | Yes | US$9.99/month (Microsoft 365 Personal, includes Office apps, 1 TB storage and monthly AI credits) |
| 3 | Gemini | Best for Gmail users | Yes | US$4.99/month (Google AI Plus, in 160+ countries) |
| 4 | ChatGPT | Best free all-rounder | Yes | US$8/month (Go, may include ads) |
1. Claude – best for getting the tone right
Free plan; good at polite-but-firm wording, shortening rambling drafts and keeping your voice.
Free plan: Free plan on web, desktop and mobile, with web search, memory and file creation; usage limits reset every five hours. Full Claude profile →
2. Microsoft Copilot – best for outlook users
Copilot chat is free with a Microsoft account; Microsoft 365 Personal (US$9.99/month in the US) adds Copilot inside Outlook and Word, with monthly AI credits.
Free plan: Copilot chat is free with a Microsoft account; Copilot inside Word, Excel and Outlook needs a Microsoft 365 plan. Full Microsoft Copilot profile →
3. Gemini – best for gmail users
Free with a Google account; paid Google AI plans add Gemini inside Gmail, so you can draft and reply without copying and pasting.
Free plan: Free with a Google account, including Deep Research, Gemini Live and image generation, with lower usage limits. Full Gemini profile →
4. ChatGPT – best free all-rounder
Its free plan handles everything from a quick reply to a formal complaint, and you can ask for two versions to choose from.
Free plan: Free plan: everyday text chats with fair-use limits, plus limited uploads, image creation, voice and deep research. Full ChatGPT profile →
Try it now: step-by-step guides
Each guide has a copy-and-paste prompt you can use with any of the tools above.
Write a tricky work email
Rough guide only: 20–40 minutes
💷 MoneyWrite a complaint to get a refund
Rough guide only: 20–30 minutes
💼 Work & careerWrite a formal letter
Rough guide only: 30–60 minutes
💼 Work & careerWrite a resignation letter
Rough guide only: 30 minutes
💼 Work & careerWrite a cover letter
Rough guide only: 30 minutes
📘 Get 20 ready-made prompts for writing emails and more
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Things to watch out for
- Check names, dates and figures – AI sometimes invents them.
- Read the email aloud before sending; cut anything you wouldn't say.
- Don't paste passwords, bank details or other people's private information into any AI tool.
How we chose
These are editorial picks by Amara Lewis, based on what each tool's free and paid plans include, how easy it is for a beginner, and how well it suits this task. We have not run formal benchmark tests for this page, and no company paid to be listed. Read how we review.
Frequently asked questions
What is the best free AI for writing emails?
Claude and ChatGPT both write good emails on their free plans. Claude tends to sound more natural; ChatGPT is quicker for lots of short replies.
Can AI write emails inside Outlook or Gmail?
Yes, on paid plans: Microsoft 365 Personal adds Copilot in Outlook, and paid Google AI plans add Gemini in Gmail. On free plans you copy the draft across.
Is it safe to paste work emails into AI?
Only use tools your employer allows, and remove confidential details, names and account numbers before pasting.
Will people know my email was written by AI?
Generic phrases give it away. Edit the draft so it sounds like you and add specific details.
Not sure where to start?
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