Copilot in Word is Microsoft's AI assistant inside Word: it drafts, rewrites, summarizes and edits from a chat pane without your document ever leaving Word. Fable is a separate desktop AI document editor where you type or speak an edit, review a diff, and keep every AI change in a version history you can restore. Both edit documents with AI. They differ in where the document lives and how changes are tracked.
This page compares the AI assistant in Word with Fable (fable.la). For Word itself as a writing tool (layout, Track Changes, file conventions), see our separate comparison of Fable vs Microsoft Word.
Last updated: October 18, 2026. Copilot details come from Microsoft's public support pages on that date. Microsoft updates Copilot often, and features vary by plan and platform.
Quick Comparison
| Fable | Copilot in Word | |
|---|---|---|
| What it is | A desktop AI document editor | An AI assistant built into Microsoft Word |
| Where your document lives | In a Fable project; import and export .docx, PDF, Markdown, HTML and text | In Word, as a .docx, usually in OneDrive or SharePoint |
| How you ask for changes | Type or speak an instruction; speech is transcribed on your computer | Type in the Copilot chat pane or on a selection |
| Drafting and rewriting | Yes, from instructions, with the whole document as context | Yes: drafts from a prompt or referenced file, rewrites selections, adjusts tone |
| Reviewing AI changes | Every edit saved with a diff, the instruction, the author, and one-click restore of any version | Suggested changes shown for review before they are added; Microsoft has been rolling out tracked changes for Copilot edits |
| Working across documents | Project assistant answers questions and proposes edits across every document in a project | Can reference other files, emails and meetings in a prompt |
| Collaboration | Owner, Editor and Viewer roles; viewer suggestions (typed or spoken) that owners accept or reject; email invites and share links | Word co-authoring, comments and Track Changes |
| Platforms | macOS and Windows desktop app | Word for Windows, Mac, web and iPad |
| Pricing | Free credits to start; Pro $20/month; optional top-ups | Included with eligible Microsoft 365 plans (usage limits apply) or a Microsoft 365 Copilot business license |
What Copilot in Word Does Well
Copilot's main strength is that nothing moves. Your document stays a Word file, with its styles, page layout, comments and tracked changes intact, in the place your organization already shares and backs up documents. For teams whose review process is built on Word, that matters more than any single feature.
Microsoft describes a broad set of abilities: drafting from a prompt, an outline or another file; rewriting a selection to be more concise or change its tone; summarizing a long document and pulling out key points or action items; answering questions about the text; and editing from the chat pane, where you describe a change from a small tweak to a document-wide revision and approve it before it is added. You can type / to bring in a related document, email or meeting as a reference. For many people, Copilot is already part of a Microsoft 365 plan they pay for.
What Fable Does Differently
Edits are the center of the app. Fable is built around one loop: say what should change, see the change, keep it or roll it back. Every edit, whether from you, a collaborator or the AI, is saved to the version history with a summary, the instruction that produced it, who made it and a diff, and any version can be restored. A long revision session leaves a readable trail rather than a single changed file.
You can speak your edits. Press record and say "tighten the second section and keep every figure," and the edit is applied. Your speech is transcribed on your own computer; only the text of the instruction is sent. See editing with AI.
It works across a project. Documents live together in a project, and the assistant answers questions across all of them ("which of these policies still mention the old office address?") and proposes edits to several documents at once as diffs you approve in one click.
Reviewers suggest rather than edit. Viewers select a passage and leave a typed or spoken suggestion; owners accept or reject it. This keeps the document under one person's control while still collecting feedback. See suggestions.
What Fable Does Not Do
- It is not a page-layout tool. Styles, headers and footers, section breaks and precise page design stay in Word. Fable exports headings, lists, tables and emphasis to .docx; layout is finished in Word.
- It does not read Word's tracked changes or comments. Resolve them before importing a .docx.
- It runs on desktop only. Fable is a macOS and Windows app; there is no web or mobile version.
- No live cursors. Collaborators' changes sync as they happen, but you do not see each other's cursors.
When to Use Which
Choose Copilot in Word if you:
- Need the document to stay in Word from start to finish, with Track Changes and comments
- Already have Copilot in your Microsoft 365 plan
- Work across Microsoft 365 and want to pull emails and meetings into a draft
- Edit on the web or on an iPad
Choose Fable if you:
- Want to give edits by voice as naturally as by typing
- Want a diff, instruction and author recorded for every AI edit, with any version one click from restored
- Work on a set of related documents and want questions and edits across all of them
- Want reviewers to suggest changes for an owner to approve
Use both if you:
Keep Word as the home for layout and final review, and do heavy revision in Fable: import the .docx, revise, export a .docx back. Our step-by-step guide to editing a Word document with AI covers the round trip, and Fable vs Word Dictate covers voice in Word. Comparing Google's assistant instead? See Fable vs Gemini in Google Docs.
Frequently Asked Questions
What is Copilot in Word?
Copilot in Word is Microsoft's AI assistant built into Word. It can draft content from a prompt or a referenced file, rewrite or change the tone of selected text, summarize a document, answer questions about it, and make changes you describe in its chat pane, which you review before they are added.
Do I need a separate subscription for Copilot in Word?
Microsoft includes Copilot in eligible Microsoft 365 consumer plans such as Personal and Family, with usage limits, and offers Microsoft 365 Copilot licenses for businesses. Availability depends on your plan and, at work, on your organization's settings, so check your Microsoft account for what is included.
How is Fable different from Microsoft Copilot in Word?
Copilot is an assistant inside Word, so your document keeps its Word formatting, tracked changes and comments throughout. Fable is a separate desktop document editor built around AI edits: you type or speak an instruction, see a diff, and every edit is saved to a version history with its instruction and author. Fable also has a project assistant that answers questions and proposes edits across all the documents in a project.
Can I use Fable and Copilot together?
Yes. Fable imports .docx files and exports .docx files, so you can do revision passes in Fable and return the document to Word for layout, tracked-changes review or final sign-off, where Copilot is available as usual.
Can I give Copilot in Word instructions by voice?
Word has its own Dictate feature for speaking text into a document; check Microsoft's current documentation for voice options in Copilot itself. Fable is designed for spoken edit instructions: you press record, say the change, and the edit is applied to the document, with your speech transcribed on your own computer.