EU Sovereignty Score
Non-EU vendorCollaborationHeadquarters: US

Slack: sovereignty score and 8 European alternatives

Slack is a cloud platform for team communication and collaboration, aimed at organisations of all sizes. Work takes place in channels and direct messages, supplemented by audio and video huddles, shared documents, lists, file sharing and Slack Connect for external partners. Workflow Builder allows no-code automation, and integrations connect Slack to other business software. AI features such as summaries are also available. Slack is delivered as software as a service through web, desktop and mobile apps, under a proprietary licence.

Slack Technologies is a US company and has been part of Salesforce since 2021. Without further configuration, customer data is stored in the United States. Customers on the Business+ and Enterprise plans can request data residency, including in Frankfurt, Paris, Stockholm and Zurich; member profiles and certain other data may remain outside that region. Slack is not open source and cannot be self-hosted. It remains a US provider, so US legislation such as the CLOUD Act can apply.

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Sovereignty score
27 / 1000 = high exposure
100 = sovereign
  • Jurisdiction SOV-210
    Headquartered in the US: CLOUD Act and FISA 702
  • Data residency SOV-350
    Hosting inside and outside Europe (US, EU)
  • Cryptographic key sovereignty SOV-320
    Key management with a non-European vendor
  • Freedom from lock-in SOV-640
    Closed source: switching requires data migration
  • Source & runtime sovereignty SOV-4 · SOV-615
    Closed source, runtime with the vendor

SOV codes: the matching objective in the European Commission's Cloud Sovereignty Framework. Official source

How the score is calculated

Facts and evidence

Last checked October 8, 2026
HeadquartersUS (US)Verified by hand
EU adequacy decisionOnly for companies individually certified under the EU-US Data Privacy FrameworkVerified by hand
Sovereignty modelVendor-hosted (non-EU)Verified by hand
Data hostingUS, EUVerified by hand
Open-sourceNoVerified by hand
GDPR-compliantYesVendor-stated
Compliance documents4 published, see belowVendor-stated
Hosting signalAMAZON-02 - Amazon.com, Inc., US (US)Technically measured
CategoryCollaboration
TypeProduct
Websiteslack.com ↗

The hosting signal shows the network that serves the vendor's website, often a CDN, and not necessarily where the service or your data is hosted. How we verify · Something wrong? Suggest a correction

Top EU-based & GDPR-compliant alternatives to Slack

The European alternatives to Slack come from our knowledge base of over 6,200 vendors. We only list vendors headquartered in the EU or the EEA; fully European-owned vendors rank before vendors with a foreign owner. For each alternative you see the country, the open-source status and a short description.

Score per alternative: 0 = high exposure, 100 = sovereign

37 European Collaboration vendors are in the catalogue. View the whole category · Submit an alternative · View category on the map

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Why digital sovereignty matters with Slack

Slack is headquartered in the United States. US vendors fall under the CLOUD Act and FISA 702: US authorities can compel access to data, even when that data sits in a European data centre. That is the core of the jurisdictional exposure in our model.

Slack hosts data in US, EU. Exactly what stays within the EU — and what does not — is defined by the vendor's data processing agreement and sub-processor list, not by a setting you control yourself; check those documents for the precise scope, including backups, logs and support access.

Slack is closed source and hosted by the vendor. The encryption keys and the runtime sit with the vendor and switching requires data migration. Ask about bring-your-own-key, export options and open standards.

What this means for your organisation depends on your whole stack and context. The free assessment weighs Slack together with your other vendors and gives a total score, a heatmap and the main risk drivers.

Frequently asked questions

What is the best European alternative to Slack?

It depends on your use case. Strong EU alternatives to Slack include Teamwire, Stackfield and Wire. On this page you can compare 8 EU alternatives by jurisdiction, data residency and open-source status.

Are there open-source alternatives to Slack?

Yes. Open-source EU alternatives to Slack include Wire, BigBlueButton (self-host), CryptPad, FluffyChat, HedgeDoc and Huly. These keep your data fully under your own control and let you self-host if you want to.

Is Slack GDPR-compliant and where is the data hosted?

Slack is headquartered in US and hosts data in US, EU. The vendor states it is GDPR-compliant, but the data falls under non-EU jurisdiction. For full EU data residency the EU alternatives on this page usually offer more certainty.

Details and sources

Verified by handHeadquarters, owner, hosting locations and licence have been checked by us against public sources. Free of charge and for every vendor, not a paid label. Nothing in this knowledge base is taken over automatically. Last checked on October 8, 2026.

Sources

Public sources used in the latest check of this record.

Compliance evidence

The links below point to the vendor's own public documents. We only record what we found: a missing link means "not found publicly", not "not compliant".

Data Processing Agreement (DPA)
slack.com/trust
Subprocessor list
slack.com/intl/en-gb/trust/compliance
Security page / trust center
slack.com/trust
EU hosting documented
slack.com/trust

Provenance of the links above:Vendor-stated

ISO/IEC 27001Vendor-statedSOC 2Vendor-stated

Links checked on September 21, 2026.

Digital sovereignty in Collaboration

Collaboration: Team communication, file sharing, video conferencing, document editing. In this category the choice of vendor determines who has legal access to your data, where that data lives and how easily you can switch later.

Also in this category

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8 European alternatives to Slack — GDPR-compliant & EU-hosted · EU Sovereignty Score