2 Best Open-Source Alternatives to Microsoft 365 in 2026
By Noahlast updated pricing verified
All 5 Microsoft 365 alternatives
Compared: open-source alternatives to Microsoft 365
| Alternative | Best for | Standout | Biggest weakness | Learning curve | Price |
|---|---|---|---|---|---|
| Microsoft 365reference | individuals and families who want the full desktop-grade Office apps plus generous cloud storage and Copilot AI synced across multiple devices, rather than free browser-only Office | A single subscription bundles full desktop-grade Word, Excel, PowerPoint, and Outlook with 1TB+ of cloud storage per person and Copilot AI built into every app, shareable across up to 6 people on Family and Premium. | There's no ongoing free tier and no mid-priced perpetual-license option: the only non-subscription path is the feature-limited $179.99 Office Home 2024, which never receives feature upgrades, so most users are locked into a recurring subscription indefinitely to keep desktop app access. | Low | From $9.99/mo |
| LibreOffice | individuals, schools, and organizations that want a full office suite without a subscription and can work without native real-time cloud co-authoring | A complete six-application office suite (including a desktop database tool in Base, which neither Microsoft nor Google offer at the consumer level) that is entirely free and open source with no feature paywall. | No native real-time multi-user co-authoring in the way Microsoft 365 or Google Workspace offer it, and complex documents with heavy Microsoft-specific formatting (advanced macros, certain chart types, some fonts) can render or convert imperfectly when round-tripped through .docx/.xlsx/.pptx. | Low | Free |
| OnlyOffice | organizations that need Microsoft Office-compatible editing but want the option to self-host on their own servers under an open-source license | AGPL 3.0-licensed source code that organizations can audit and self-host, combined with a DocSpace pricing model that charges only for admin seats while unlimited regular users join free. | Business Cloud pricing is per-admin rather than per-user, which can be confusing to compare against competitors, and users switching from Microsoft Office report formatting fidelity issues on complex documents with heavy macros or advanced layout. | Moderate | Free tier · paid from $20/mo |
Microsoft 365
LibreOffice
OnlyOffice1.LibreOffice — best Microsoft 365 alternative for individuals, schools, and organizations that want a full office suite without a subscription and can work without native real-time cloud co-authoring
LibreOffice is the best Microsoft 365 alternative for anyone who wants to stop paying a subscription and can work without cloud co-authoring. LibreOffice is free with no paid tier, no account requirement, and no feature gating, which saves the $99.99/year Microsoft 365 Personal costs, and it is six applications rather than the four or five in a Microsoft 365 consumer plan: Writer, Calc, Impress, Draw for vector graphics and diagrams, Base for desktop databases, and Math for formulas. It reads and writes .docx, .xlsx, and .pptx alongside its native OpenDocument formats, and it runs on Linux as well as Windows and macOS, shipping as the default suite on many Linux distributions where Microsoft 365 has no Linux client. Development is funded by The Document Foundation under the MPL-2.0 license with parts under GPL and LGPL. Microsoft 365 remains the better choice for teams and mobile users. LibreOffice has no native real-time co-authoring, so simultaneous multi-user editing is not built in, and it has no official iOS or Android apps, where Microsoft 365 covers web, Windows, macOS, iOS, and Android. Complex Microsoft-format documents with advanced macros, certain chart types, and some fonts can lose fidelity in conversion, there is no bundled cloud storage against Microsoft 365's 1TB per person, and no Copilot AI of any kind.
Compared to Microsoft 365: $0 with no paid tier against Microsoft 365 Personal's $99.99/year, six applications including Base and Draw against the Microsoft 365 consumer bundle, and a native Linux build Microsoft 365 does not offer
Wins:Free with no subscription, no account, and no feature paywall, saving the $99.99/year Microsoft 365 Personal costs · Six applications (Writer, Calc, Impress, Draw, Base, Math), including a desktop database tool and a vector graphics app the Microsoft 365 consumer plans do not include · Runs natively on Linux and ships as the default suite on many Linux distributions, a platform Microsoft 365 does not cover
Loses:No native real-time co-authoring, so simultaneous multi-user editing is not built in the way it is across Microsoft 365 · No official iOS or Android apps, where Microsoft 365 covers web, Windows, macOS, iOS, and Android · No bundled cloud storage against Microsoft 365's 1TB per person and no Copilot AI, and complex .docx/.xlsx/.pptx files with advanced macros or charts can lose fidelity
Pros
- Completely free with no subscription, account, or feature paywall, including a desktop database app (Base) most competitors omit.
- Open source (MPL-2.0/GPL/LGPL) with an active community and frequent releases.
- Broad Microsoft Office format compatibility (.docx, .xlsx, .pptx) for opening and editing existing Office files.
- Runs on Windows, macOS, and Linux, and is the default suite on many Linux distributions.
Cons
- No native real-time cloud co-authoring like Microsoft 365 or Google Workspace, so simultaneous multi-user editing isn't built in.
- Complex Microsoft-format documents (advanced macros, some chart and font rendering) can lose fidelity when converted.
- No official mobile apps for iOS/Android under the LibreOffice brand.
- Interface and default styling feel dated compared to Microsoft Office or Google Workspace.
Pricing: Free — $0 with no subscription or paid tier vs Microsoft 365 Personal's $9.99/month ($99.99/year) (verified undefined NaN, NaN)
2.OnlyOffice — best Microsoft 365 alternative for organizations that need Microsoft Office-compatible editing but want the option to self-host on their own servers under an open-source license
ONLYOFFICE is the best Microsoft 365 alternative for organizations that need Microsoft-compatible editing but cannot put documents in a vendor's cloud. ONLYOFFICE publishes its source under the AGPL 3.0 license on GitHub, and both the desktop editors and the Community Server are free to self-host on an organization's own infrastructure, an option Microsoft 365 offers no equivalent to. Its hosted DocSpace platform prices by admin rather than by user: the Startup tier is free with up to 3 admins, unlimited users and guests, 2GB per space and up to 12 rooms, and Business Cloud is $20/admin/month (discounted from $30) with 250GB per admin, unlimited rooms, and unlimited regular users invited free. For a 20-person group that is $20/month on one admin seat, where Microsoft 365 has no consumer plan covering more than the six people on Family at $12.99/month. Co-editing tracks changes at character level, and built-in AI handles content generation, translation, and text extraction from scanned documents. Microsoft 365 is still the better choice for individuals and for complex documents. ONLYOFFICE holds 4.5/5 from only 324 Capterra reviews against Microsoft 365's 4.6/5 from 14,143, users switching from Microsoft Office report fidelity loss on documents with heavy macros or advanced layout, free DocSpace gives just 2GB per space against Microsoft 365's 1TB per person, and Enterprise on-premises pricing is unpublished and billed per connection.
Compared to Microsoft 365: AGPL 3.0 source you can self-host on your own servers, a free DocSpace Startup tier where Microsoft 365 has no free plan, and per-admin pricing at $20/admin/month with unlimited regular users invited free
Wins:AGPL 3.0 source on GitHub with free self-hosted desktop editors and Community Server, so documents can stay entirely on-premises · Free DocSpace Startup plan (3 admins, unlimited users and guests, 2GB per space, 12 rooms) where Microsoft 365 has no free tier · DocSpace Business Cloud charges $20/admin/month with unlimited regular users free, so a 20-person group runs on one paid seat, and native apps cover Windows, macOS, Linux, iOS, and Android plus 40+ integrations including Nextcloud and Moodle
Loses:4.5/5 from just 324 Capterra reviews against Microsoft 365's 4.6/5 from 14,143, a far thinner evidence base · Documents with advanced Word or Excel formatting and macros can lose fidelity, a recurring report from users switching off Microsoft Office · Free DocSpace gives 2GB per space and Business Cloud 250GB per admin, against Microsoft 365's 1TB per person, and Enterprise on-premises pricing is unpublished and billed per connection
Pros
- AGPL 3.0 source code available on GitHub; fully self-hostable for organizations that need to keep data on-premises.
- DocSpace charges only for admin seats, with unlimited regular users invited free.
- Native apps across Windows, macOS, Linux, iOS, and Android, plus 40+ third-party integrations including Nextcloud and Moodle.
- Real-time co-editing with character-level change tracking and built-in AI content tools.
Cons
- Complex documents with advanced Word/Excel formatting or macros can lose fidelity when opened in ONLYOFFICE.
- Enterprise on-premises pricing is not published; requires a sales conversation.
- Per-admin pricing model on Business Cloud takes more effort to compare against per-user competitors.
- DocSpace's interface is less polished than Google Workspace or Notion for non-technical teams.
Pricing: Free tier · paid from $20/mo — Free DocSpace Startup (3 admins, 2GB per space) or $20/admin/month with unlimited free users, vs Microsoft 365 Personal's $9.99/month for one person with 1TB (verified undefined NaN, NaN)