Sovereign office suites: alternatives to Microsoft 365 and Google Workspace in 2026

For years, choosing an office suite was not really a choice. You ran Microsoft 365 or Google Workspace, your documents lived on American servers, and nobody asked harder questions. In 2026 that has changed. Data sovereignty has gone from a compliance footnote to a board-level concern, public administrations across Europe are actively migrating off US suites, and a real field of open-source and European alternatives has grown up to meet them.

This guide is the map. It is written for IT teams, public-sector operators, and MSPs who have to evaluate office suites as infrastructure, not just as the thing that opens spreadsheets. We will cover what a suite actually has to do for a team, why sovereignty is now a buying criterion, and which tools fit which kind of organization. As always, there is no universal winner here, only a right answer for your situation.

Short verdict:

• Microsoft 365 and Google Workspace remain the most capable suites, and the benchmark everyone else is measured against. The cost is sovereignty: US-headquartered providers carry Cloud Act exposure that data residency alone does not fix.
• La Suite numérique, OnlyOffice, Euro-Office, Collabora, LibreOffice, and Infomaniak kSuite are the credible open-source and European options, each making a different trade between control, polish, and effort.
• The right choice depends on who you are: public sector, SME, association, regulated shop, or homelab each point to a different tool.

What an office suite actually has to do

Before any product names, get clear on the job. For a team, autofilling a template is the least of it. The things that decide whether a suite works at organizational scale are:

• Real-time co-authoring. Multiple people editing the same document without emailing versions around. This is now table stakes, and it is exactly where the older open-source suites historically struggled.
• Format fidelity. Whether Word and Excel files survive a round trip without breaking. For most organizations, OOXML compatibility is non-negotiable because the rest of the world still sends .docx.
• Drive and sharing. Where files live, how they are shared, and how permissions are managed.
• Admin and identity. Provisioning, deprovisioning, SSO, and policy enforcement.
• Hosting model. Hosted SaaS, self-hosted, or a sovereign third party, each with very different operational and legal consequences.

Every recommendation below is an answer to which of these your organization weighs most. Decide that first.

Why sovereignty became a buying criterion

The shift is not fashion, it is law and politics catching up with reality. A US-headquartered provider can be compelled under the US Cloud Act to produce data regardless of where that data physically sits, which is why “our data is stored in an EU region” no longer ends the conversation. The EU Data Boundary and various “sovereign controls” reduce residency risk but do not remove that extraterritorial reach.

In response, France built SecNumCloud qualification through its security agency ANSSI, and adopted a “cloud at the centre” doctrine that pushes sensitive public data toward providers insulated from non-EU law. Source: SecNumCloud and sovereign cloud (Legiscope). Press reporting through 2026 describes public administrations setting deadlines to cut non-European dependencies, and several German and French bodies migrating off Microsoft entirely. Treat the exact figures as directional, but the direction is unmistakable: for a growing set of organizations, the passport of the provider is now part of the spec.

If sovereignty is irrelevant to you, the incumbents are excellent and you should read this guide for the feature trade-offs alone. If it is on your list, the rest of the field suddenly matters a great deal.

The open-source and European field

This is where the interesting choices live. A quick orientation:

• La Suite numérique is the French government’s own open-source suite, built by DINUM. It bundles a collaborative document editor (Docs), a spreadsheet/no-code database (Grist), a drive, and video (Visio). It is the reference implementation of a sovereign public-sector workplace, though its hosted instance is reserved for state agents.
• OnlyOffice is the most polished open-source suite for Microsoft-format fidelity and browser-native editing. It also carries a genuine provenance debate around its Russian origins, which is worth understanding rather than hand-waving.
• Euro-Office is the 2026 European fork of OnlyOffice, led by Nextcloud and IONOS, created specifically to put the project under European governance. It is the most newsworthy entry in the field, and the most nuanced.
• Collabora Online and LibreOffice are the LibreOffice-family answer: Collabora for self-hosted real-time editing, LibreOffice for the desktop/ODF gold standard. They carry no provenance baggage.
• Infomaniak kSuite is the Swiss, privacy-first hosted option for teams that want sovereignty without running their own servers, with document editing powered by OnlyOffice under the hood.

We review each of these in dedicated articles in this series, and compare the self-hostable engines head to head, so you can go deep on whichever shortlist survives this page.

The incumbents as the benchmark

It would be dishonest to pretend the open-source field has caught up on every axis. Microsoft 365 and Google Workspace are still the most capable, most integrated suites, and they set the bar for the alternatives.

Microsoft’s strength is the fabric: Word, Excel, and PowerPoint tied to OneDrive, SharePoint, Teams, and the newer Loop canvas, all co-authored in real time. Google’s strength is collaboration itself, since Docs, Sheets, and Slides effectively invented browser-native multi-user editing and still do it as smoothly as anyone. Both are sticky precisely because everything is one connected system.

The catch is the one this whole guide is about. Both are US-headquartered, both carry Cloud Act exposure, and both lock you into proprietary formats and ecosystems that raise the cost of ever leaving. For many teams that trade is fine. For a growing number, it is exactly the trade they are trying to undo. We cover the document and collaboration side of each, deliberately setting their email products aside, in their own articles.

How to choose by organization type

Strip away the names and the decision usually follows from who you are:

• Public sector / government. La Suite numérique if you are eligible for the state instance, or self-hosted, with the cooperative route as an alternative for bodies that cannot use the hosted version.
• SME wanting sovereignty without ops burden. A sovereign hosted suite like Infomaniak kSuite, or the cooperative hosting of the French stack. You get European jurisdiction without running servers.
• Self-hosting team or homelab. OnlyOffice, Euro-Office, or Collabora on your own infrastructure, chosen by how you feel about provenance and how much real-time editing you need.
• Regulated or sovereignty-critical org. Open-source and European-governed first, with self-hosting or a SecNumCloud-aligned provider, so you can answer the extraterritorial-law question cleanly.
• Team that just wants maximum capability and does not care about sovereignty. Microsoft 365 or Google Workspace. They are the benchmark for a reason.

The recurring mistake is buying for sovereignty optics without the operations to back it, or buying maximum capability without noticing the sovereignty cost. Match the suite to what you actually have to defend.

Final verdict

The office suite has quietly become a sovereignty decision. The incumbents, Microsoft 365 and Google Workspace, remain the most capable and the benchmark for everyone else, but their US provenance is now a real cost rather than a non-issue. Against them stands a maturing field of open-source and European options, La Suite numérique, OnlyOffice, the Euro-Office fork, Collabora and LibreOffice, and sovereign hosts like Infomaniak kSuite, each trading polish for control in a different way.

Start from your own constraints. If sovereignty is a hard requirement, the European and open-source field is now strong enough to take seriously, and the rest of this series goes deep on each option so you can build a real shortlist. If it is not, the incumbents are excellent and the choice is easier. Either way, the era of running an American suite by default, without ever asking why, is over.

If your sovereignty thinking extends to the rest of your stack, it is worth applying the same lens to credentials: we did exactly that in our guide to the best self-hosted password managers for small IT teams.