whats-best.ai
Search Sign in

Business Instant Messaging

Slack

Rest of world Report an error

Panel rating · 6 judges · How to read the stars

Category median

Sovereignty: not determined

0–5 in half steps. 5 means the rubric's top anchor is met on the evidence.

by Salesforce, Inc. · slack.com

Compare with Mattermost → Compare with Microsoft Teams (Chat) → Report an error on this page Is this your product? →

Read this page as one judge. Each weighs the same scores by what they care about.

The Works Council Advocate

Weighted verdict

Knows that a chat log is a record of who spoke to whom at what hour. Wants presence a person controls, no individual activity scoring anywhere, retention that deletes rather than hides, and analytics that can be switched off across the organisation.

Same scores as the panel view — this lens weights them the way this judge cares.

Scored by The Works Council Advocate

Channels, threads & search

How this is scored

The daily surface: channel model, threading, mentions, files, and whether search can find a decision made eighteen months ago.

0 — Flat group chats with no threads; search covers recent messages only, and history is capped.

3 — Channels and direct messages with basic search, but threading is awkward or absent and file handling is a plain attachment list.

5 — Public and private channels, real threads, mentions and reactions, file sharing with previews, and full-text search across the whole history.

8 — Cross-organisation or guest channels with clear boundaries, message editing history, pinned and saved items, search with filters by channel, person and date, and a documented history limit or none at all.

10 — The archive is a working knowledge base: search that ranks well across years, threads that stay readable, channel lifecycle management (archive, rename, merge) without losing history, and export of a conversation in a form a human can read.

Report an error

The Works Council Advocate

Channels, Slack Connect with 4M external users, file sharing and AI search across stored company knowledge are evidenced, with documented history limits (free: 1 year, paid: unlimited). But the evidence says nothing about threads, message edit history, or exporting a conversation a human can read — for a chat log to be a record, I need that archive story, not just search. 1 2 2

Report an error

Encryption & access control

How this is scored

What is encrypted and against whom, plus who can reach which room. Judged on documented mechanism, since "encrypted" in this category usually means the vendor holds the keys.

0 — Transport encryption only, undocumented; no role model beyond admin, guests indistinguishable from members.

3 — TLS and encryption at rest with vendor-held keys, basic roles, and guest access that mostly works.

5 — The above plus configurable roles per channel, SSO, guest accounts with scoped visibility, and a clear statement of what the vendor can read.

8 — Optional end-to-end encryption for direct messages or private rooms with the trade-offs named, device verification, session management an admin can revoke, and documented key handling.

10 — End-to-end encryption as a first-class mode — documented or open cryptography, cross-device key management that ordinary users survive, identity verification, and the vendor stating plainly what it cannot decrypt.

Report an error

The Works Council Advocate

Encryption at rest and in transit with vendor-held keys by default; Enterprise Key Management is only a paid add-on, which is the right direction but not first-class. SSO, 2FA, information barriers and admin control over DM visibility and external connections are documented, but there is no end-to-end mode and no plain statement of what Slack itself can read. 1 2 3 2

Report an error

Retention, discovery & co-determination

How this is scored

The archive as a legal object: retention policies, export for discovery, audit, and the monitoring features a works council will ask to have switched off.

0 — No retention policy, no export beyond a manual copy, no audit log, and presence or activity analytics that cannot be disabled.

3 — Manual export of some data and a global history limit, but no per-channel retention, no audit log and no admin control over analytics.

5 — Configurable retention per channel or workspace, admin export in a documented format, an audit log of administrative actions, and status or presence that a user can control.

8 — Legal-hold and eDiscovery export including edits and deletions, retention executed per policy and evidenced, full admin audit trail, and activity analytics switchable off organisation-wide.

10 — Built to pass a works agreement and a subpoena on the same day: granular retention with documented deletion, discovery export a lawyer can use, complete audit, and no individual-level productivity scoring anywhere in the product.

Report an error

The Works Council Advocate

Retention is configurable at workspace and channel level, and legal hold, audit logs and native DLP exist — but the evidence is silent on discovery export in any format, on whether deletion is evidenced, on user-controlled presence, and on switching analytics off organisation-wide. A works agreement cannot rest on half of rubric level 5; those absences are information. 2 3

Report an error

Deployment & data custody

How this is scored

Whether the customer can hold their own archive: self-hosting, private cloud, open source, federation, and what an exit actually looks like.

0 — Cloud-only, proprietary, with export limited to a partial archive.

3 — Cloud-only, but with a documented full export in an open-ish format.

5 — A private-cloud or dedicated-instance option, or a self-hosted edition that lags the cloud significantly; full export documented.

8 — A genuine self-hosted edition close to feature parity, or open-source core with a documented upgrade path, plus complete export including files and metadata.

10 — Custody is the customer's: open-source or source-available server, self-hosting supported as a first-class deployment, open protocol or federation, and a migration path in and out that the vendor documents rather than resists.

Report an error

The Works Council Advocate

Cloud-only and proprietary: no self-hosting, no open source, no federation, and no documented full export anywhere in the evidence — not even the partial one rubric level 0 would still allow scoring. Germany data location from Business+ and LLMs in Slack's own AWS cloud are residency, not custody; the archive belongs to Salesforce either way. 2 2

Report an error

Integrations & extensibility

How this is scored

Bots, webhooks, app framework, identity — whether the chat becomes the place work is noticed, and whether that is buildable without a partner agreement.

0 — No API, no webhooks, no bots.

3 — Incoming webhooks and a handful of native integrations; no bot framework, no documented limits.

5 — Documented REST API, incoming and outgoing webhooks, slash commands, a bot account model, and SSO.

8 — A proper app framework with interactive components, event subscriptions with retries, SCIM provisioning, documented rate limits and a sandbox.

10 — A platform: versioned API with a deprecation policy, an app directory or plugin system with permissions a customer can audit, and integrations the vendor maintains rather than lists.

Report an error

The Works Council Advocate

SSO, SCIM provisioning, a workflow builder usable with or without code, and named integrations (Google Drive, ChatGPT, Asana, Workday) with workspace-level allow/restrict control are all evidenced. But the evidence captures no documented API, no webhook model, no rate limits or sandbox — I cannot credit a platform on integration logos alone. 1 2 3

Report an error

European sovereignty

How this is scored

Where the archive and its metadata live, who the contracting entity is, which subprocessors touch it. Independently sourced by the sovereignty pipeline; scored here as this buyer weighs it.

0 — Non-EU vendor and contracting entity, hosting unstated or non-EU, subprocessors unnamed.

3 — EU data residency offered for message content while metadata, search indexes or support tooling remain non-EU, or the contracting entity sits outside the EU.

5 — EU hosting as standard and an EU contracting entity, but parts of the chain — notifications, AI features, analytics — are non-EU without an explained safeguard.

8 — EU hosting on named infrastructure, EU contracting entity, full subprocessor list published, any non-EU processing named with its legal basis.

10 — Sovereign end to end and evidenced: vendor, entity, hosting and every subprocessor European, certification published, and a self-hosted option that removes the question.

Report an error

The Works Council Advocate

Germany data residency exists but only from Business+ upward, while the contracting entity is Salesforce, Inc. of San Francisco and the subprocessor chain is unnamed — exactly the rubric level 3 situation. The LLMs run in Slack's own AWS private cloud and ChatGPT is a showcased integration with no legal basis or safeguard stated for that reach. 1 2 2

Report an error

Pricing transparency

How this is scored

Whether a buyer can compute the annual invoice for their headcount — including the retention, compliance and guest features they actually need — from public pages alone.

0 — No public prices at all; every tier is a sales conversation.

3 — A per-user headline exists, but the tier where retention control, SSO or compliance export begins is unstated.

5 — Per-user prices public with billing period stated, but at least one commonly needed capability (unlimited history, SSO, eDiscovery) sits in an unpriced enterprise tier.

8 — Every tier priced publicly with per-user maths, history and storage limits, feature boundaries, minimum term and VAT treatment stated; self-hosted licensing priced too where offered.

10 — Complete price computability: annual invoice derivable for a given headcount and deployment choice, including guest users, storage and any per-instance licence.

Report an error

The Works Council Advocate

Tier boundaries are genuinely public — which plan gets unlimited history, legal hold, audit logs, SCIM, Germany hosting and which SLA — and VAT-compliant invoices are downloadable. But not a single per-user price figure appears in the captured pricing pages, and Enterprise Key Management is an unpriced add-on, so the annual invoice for our headcount is not computable from what is published here. 2 2

Report an error

European sovereignty — proven facts

0 of 4 dimensions proven

Built only from facts shown on the vendor's own pages. A dimension we could not prove is left open, not scored as zero.

Ownership Not determined ⚠ unverified — uncited Report an error
Data residency Not determined ⚠ unverified — uncited Report an error
Subprocessors Not determined ⚠ unverified — uncited Report an error

Where this could be wrong

What we left out

A claim that does not survive our checks costs us the claim, not the page. This is what was taken off this one.

Do you know more about Slack? Tell us Report an error on this page

Sources (12)

The pages every claim on this page was read from — each one checked, dated, and kept verifiable.

  1. 1 Vendor homepage slack.com Checked 15 Sep 2026 Details →
  2. 2 Pricing slack.com Checked 15 Sep 2026 +1 earlier capture: 15 Sep 2026 Details →
  3. 3 Privacy policy slack.com Checked 15 Sep 2026 Details →
  4. 4 Legal notice slack.com Checked 21 Sep 2026 Details →
  5. 5 Channels, threads & search — found from sitemap slack.com Checked 1 Oct 2026 Details →
  6. 6 Channels, threads & search — found from sitemap slack.com Checked 1 Oct 2026 Details →
  7. 7 Encryption & access control — found from sitemap slack.com Checked 1 Oct 2026 Details →
  8. 8 Encryption & access control — found from sitemap slack.com Checked 1 Oct 2026 Details →
  9. 9 Retention, discovery & co-determination — found from sitemap slack.com Checked 1 Oct 2026 Details →
  10. 10 Retention, discovery & co-determination — found from sitemap slack.com Checked 1 Oct 2026 Details →
  11. 11 Integrations & extensibility — found from sitemap slack.com Checked 1 Oct 2026 Details →
  12. 12 Integrations & extensibility — found from sitemap slack.com Checked 1 Oct 2026 Details →