OpenAI has planted ChatGPT directly inside Microsoft Word. As of 17 September, a new add-in puts ChatGPT in a sidebar within Word itself, where it will draft, revise, proofread, summarise and format without you ever leaving the document. Word now joins Excel and PowerPoint, which already had the same treatment, so ChatGPT is officially living inside the big three Office apps. The genuinely notable bit: it is available on every ChatGPT plan, including the free tier.
What it actually does
You install it from the Microsoft Marketplace and it appears as a panel beside your document. From there it behaves like ChatGPT, except it can see and act on the text you are working on: rewrite a clunky paragraph, tighten a summary, fix your grammar, reformat a section, or draft something new from a prompt, all in place. The friction it removes is the copy-paste shuffle between a browser tab and your document, which sounds trivial until you realise how much of “using AI to write” is really just ferrying text back and forth.
On the practical stuff: your plan’s token limits apply, and on paid plans Word draws from the same shared allowance as Codex and other premium features, so heavy users will feel the meter. But for the free tier to get a capable AI assistant embedded in Word at no cost is a real shift, and it is worth actually installing rather than shrugging at.
Why it matters
Distribution is the whole game here. Hundreds of millions of people live in Word every working day, and OpenAI has now put ChatGPT one sidebar-click away from all of them, free. That is a land grab dressed as a convenience feature. For most people the takeaway is simple and useful: if you write in Word, this is the fastest way yet to have an AI help without changing how you work. Install it, try it on a real document, and see whether the sidebar earns its place. Our steer: it will, for editing and summarising; be more sceptical of letting it draft from scratch, where it still needs a firm human hand.
Related: Claude vs ChatGPT vs Gemini for writing.