# 2 Best Open-Source Alternatives to Microsoft 365 in 2026

By Noah — last updated & pricing verified September 15, 2026.

> 2 of the 5 Microsoft 365 alternatives we list qualify for this filter. The [full list](https://findalternative.to/microsoft-365) is the canonical page.

| Alternative | Best for | Price | Details |
| --- | --- | --- | --- |
| LibreOffice | individuals, schools, and organizations that want a full office suite without a subscription and can work without native real-time cloud co-authoring | Free | https://findalternative.to/libreoffice/about |
| OnlyOffice | organizations that need Microsoft Office-compatible editing but want the option to self-host on their own servers under an open-source license | Free tier · paid from $20/mo | https://findalternative.to/onlyoffice/about |

All 5 alternatives to Microsoft 365: https://findalternative.to/microsoft-365

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Markdown mirror of https://findalternative.to/microsoft-365/open-source — findalternative.to, honestly ranked software alternatives. AI info: https://findalternative.to/ai