Free, open-source alternatives to Microsoft 365
Microsoft's office suite with cloud storage. 6 apps you can run yourself instead of Microsoft 365, sorted by how well they replace it. Each one is open source, so your data stays with you.
NextcloudBest match
Access and share your files, calendars, contacts, mail and more from any device, on your terms.
ONLYOFFICE
Office suite that enables you to manage documents, projects, team and customer relations in one place.
Collabora Online Development Edition
Collabora Online Development Edition (CODE) is a powerful LibreOffice-based online office that supports all major document, spreadsheet and presentation file formats, which you can integrate in your own infrastructure.
CryptPad
Collaboration suite built to enable collaboration, synchronizing changes to documents in real time.
egroupware
Software suite including calendars, address books, notepad, project management tools, client relationship management tools (CRM), knowledge management tools, a wiki and a CMS.
Zimbra Collaboration
Email, calendar, collaboration server with Web interface and lots of integrations.
Side by side
| App | Stars | License | Activity | Runs on |
|---|---|---|---|---|
| Nextcloud | 37,081 | AGPL-3.0 | PHP, Debian packages | |
| ONLYOFFICE | 6,999 | AGPL-3.0 | Node.js, Docker | |
| Collabora Online Development Edition | - | MPL-2.0 | C++ | |
| CryptPad | 8,005 | AGPL-3.0 | Node.js, Docker | |
| egroupware | 297 | GPL-2.0 | PHP | |
| Zimbra Collaboration | - | GPL-2.0, CPAL-1.0 | Java |
Why replace Microsoft 365?
Microsoft 365 works, but your data lives in someone else's account, the price can change at any time, and features can disappear. An open-source app you run yourself is yours: you choose where it runs, who can see the data, and when to update.
Questions
What is the best free alternative to Microsoft 365?
Nextcloud is the closest open-source replacement for Microsoft 365 in our list. ONLYOFFICE and Collabora Online Development Edition are worth a look too, depending on what you need.
Can I self-host an alternative to Microsoft 365?
Yes. All 6 apps on this page are open source and can run on your own server, usually with Docker, or on a managed host that installs them for you.