Last checked Nov 3, 2026
The short answer
If you need Microsoft's full feature set, real-time co-authoring and the cloud around it, Microsoft 365 is still the standard and Arkemis Office will not replace it today. If what you mostly do is write, calculate, present and mark up PDFs, and you would rather not pay a subscription for it, Arkemis Office covers the everyday work for free.
Arkemis Office is a preview. It is newer, smaller and rougher at the edges than Microsoft's apps, and complex layouts can differ slightly when you open a heavily formatted Word or PowerPoint file.
Side by side
| Arkemis Office | Microsoft 365 | |
|---|---|---|
| Price | Free, no account | Paid subscription |
| Runs on | Windows and Mac | Windows, Mac, web and mobile |
| Apps | Quill (documents), Grid (spreadsheets), Prism (slides), Slate (notes), PDF editor | Word, Excel, PowerPoint, OneNote, Outlook and more |
| File formats | Opens and saves .docx, .xlsx and .pptx | Native Office formats |
| AI | Arkemis's AI inside each app and the notch can write and edit the open file; AI features run on your Arkemis plan | Microsoft Copilot, sold separately |
| Collaboration | Files stay on your own disk; no real-time co-authoring | Real-time co-authoring and cloud storage |
| Maturity | Preview (0.1.x) | Decades of development |
Where Arkemis Office is different
- Free: every editing tool is free to install and use. There is no trial clock and no sign-in.
- AI that works in the file: the Arkemis notch can write the paragraph, fill the sheet or build the slide inside the open document, and asks before anything leaves your hands.
- Your files stay yours: documents open and save on your own disk. Nothing is uploaded to use the editors.
- One plan for the AI: the AI in Arkemis Office runs on the same Arkemis plan as the notch, browser use and computer use, so there is no separate add-on.
Using them together
Because Arkemis Office opens and saves the same file formats, you can keep Microsoft 365 for the documents that need it and use Arkemis Office for the rest. Arkemis is independent and not affiliated with Microsoft. Microsoft 365 details come from Microsoft's public pages as of Nov 3, 2026; check them for current plans.