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Comparison

Enclessa vs Slack

Slack is a proprietary messaging platform operated by Salesforce, with an established third-party app directory and an interaction design most teams already know. Enclessa is a commercial hosted service run in the European Union, and encrypts direct messages end to end with MLS so that the operator of the service cannot read them. Slack offers customer-managed encryption keys on its top tier, which is a real control and a different thing from end-to-end encryption: the service still processes plaintext.

Open betaThe platform is being built in the open, so parts of it are not there yet, behaviour changes between releases, and no availability figure is committed while it is in beta. What is still being built.

Side by side

Enclessa compared with Slack
DimensionEnclessaSlack
What is published for reviewArchitecture, data model, OpenAPI surface and encryption designProduct documentation and a trust centre
End-to-end encryptionDirect and group direct messages, MLS per RFC 9420Not offered. Enterprise Key Management provides customer-controlled keys, with the service still processing message content
HostingEuropean Union; a dedicated deployment on Enterprise, operated by usOperated by Salesforce, with regional residency options on higher tiers
Message historyRetained per your own retention policyHistorically limited on lower tiers; check the current plan terms
Third-party appsNone. First-party modules only, no runtime third-party codeAn established third-party app directory
Included modulesTask boards, GitHub sync, time tracking, HR recordsAvailable through third-party apps
Video callsGroup calls with screen sharing, lobby and host controlsHuddles, plus integrations with dedicated meeting products
LeavingFull organisation export; documented data model and OpenAPIExport tooling varies by plan

Statements about other products come from their own public documentation and describe the position as last checked on 18 August 2026. Vendors change what they offer; check the current documentation before making a decision on the strength of this page.

Why teams pick Enclessa

Customer-managed keys are not end-to-end encryption

Holding the key in your own key management service is a genuine control, and it is not the same as the service being unable to read the message. In Enclessa the server never has a key for an encrypted room, so the distinction does not depend on a configuration being right.

European hosting on every plan

Where the data sits is not a feature reserved for the top tier. The service runs in the European Union for every customer.

The work, not only the talking

Boards, GitHub sync, time tracking and personnel records are modules of the same platform under one permission model, instead of four subscriptions stitched together with apps.

A retention policy you set

History is kept according to your organisation’s retention rules rather than according to which plan you are on.

When Slack is the better choice

This section is here because a comparison page without one is an advertisement. If any of these describe you, buy the other product.

Your workflow depends on the app directory

Slack’s ecosystem is its strongest asset and Enclessa deliberately runs no third-party code. If a vendor’s Slack app is central to how you work, that is decisive.

You work across many external organisations

Shared channels between companies are something Slack does well and Enclessa does not offer.

Familiarity has a real cost for you

Most knowledge workers already know Slack. If your rollout budget is thin and confidentiality is not a driver, that familiarity is worth money.

Where to next

Questions

vs Slack: common questions

Is there an open source alternative to Slack?

Enclessa is not one: it is a commercial hosted service and its source is not published. Mattermost is the best-known open-source option and is oriented towards self-hosting. What Enclessa offers in place of readable source is end-to-end encrypted direct messages using MLS per RFC 9420, a published architecture, data model and OpenAPI surface, European hosting, and a full organisation export in open formats at any time.

Does Slack have end-to-end encryption?

Slack does not offer end-to-end encryption of messages. Its Enterprise Key Management feature lets a customer control the encryption keys, but the service still processes message content. Enclessa encrypts direct and group direct messages end to end with MLS, so the server holds no key that opens them.

Can Enclessa import our Slack history?

Not today. There is no Slack import tool. Organisations that move typically keep the Slack export as an archive and start fresh in Enclessa.

Encrypted collaboration, hosted in Europe.

Create a workspace in a couple of minutes. It is yours at your-team.enclessa.app, hosted in the European Union, with encrypted direct messages from the first one you send.

Open beta. Free plan, no payment card to start.