Business Instant Messaging · head-to-head
Microsoft Teams (Chat) vs Slack
The short answer
Slack leads messaging core 6.5 to 2.5, encryption and access 5.3 to 2.3, governance and discovery 5.5 to 2.5 and sovereignty 2.8 to 0.7 — each a six-to-zero lean for Slack — and integrations 5.8 to 3.8, five judges leaning Slack with one tie. Microsoft Teams (Chat) is ahead on pricing transparency alone, 4.0 to 3.7: three judges lean Teams, one leans Slack, two tie, and its verdict cites add-on prices published exactly — Teams Premium at 8,70 € per user per month, VAT excluded — where the Slack verdict records no per-user price, leaving the annual invoice not computable. Deployment control nearly ties, 1.0 to 1.3, four ties and two judges leaning Slack. The listed sovereignty attributes match on IE jurisdiction, US by default residency and US CLOUD Act reach exposure, with ownership unknown for Teams and foreign-controlled for Slack. Persona-weighted totals span 1.8 to 3.3 for Teams and 4.0 to 4.9 for Slack.
Choose Microsoft Teams (Chat) if
- You must compute the annual invoice before signing — pricing transparency leans Microsoft Teams (Chat) three judges to one, with add-on prices published exactly, while the Slack verdict records no per-user price and an annual invoice that is not computable.
- Your finance approval needs exact public per-user prices — Teams Premium at 8,70 € per user per month and Microsoft 365 Copilot Business at 18,20 € per user per month, VAT excluded, are published.
- Your vendor policy screens out foreign-controlled ownership — the sovereignty attributes list Slack as foreign-controlled and record Microsoft Teams (Chat)'s ownership as unknown.
- Your evaluation weights published pricing most heavily — pricing transparency is the one criterion where Microsoft Teams (Chat) leads on means, 4.0 to 3.7, and on leans, three judges to one.
Choose Slack if
- You weigh messaging core first — it leans Slack six judges to zero, mean 6.5 to 2.5, credited for channels, Slack Connect cross-organisation rooms, AI search over stored knowledge and unlimited message history from Pro.
- Your security review scores encryption and access heavily — that criterion leans Slack six judges to zero, mean 5.3 to 2.3.
- You must run retention, legal hold and DLP — governance and discovery leans Slack six judges to zero, mean 5.5 to 2.5.
- Your platform engineers want a buildable surface — integrations leans Slack five judges to one tie, mean 5.8 to 3.8, with the platform engineer crediting 1.7 million weekly active apps.
- You need Germany data residency — sovereignty leans Slack six judges to zero, mean 2.8 to 0.7, and the verdict records Germany residency purchasable from Business+.
Read this comparison as one judge. Each weighs the same scores by what they care about.
The bench's picks
Same scores, different priorities: each judge's weighting applied to both products. The split is the finding.
- The Team Lead Microsoft Teams (Chat) Slack picks Slack
- The Security Officer Microsoft Teams (Chat) Slack picks Slack
- The Works Council Advocate Microsoft Teams (Chat) Slack picks Slack
- The Compliance Counsel Microsoft Teams (Chat) Slack picks Slack
- The Platform Engineer Microsoft Teams (Chat) Slack picks Slack
- The Skeptic Microsoft Teams (Chat) Slack picks Slack
Criterion by criterion
| Criterion | Microsoft Teams (Chat) | Slack | The bench leans |
|---|---|---|---|
| Channels, threads & search | Slack, 6 of 6 judges | ||
| Encryption & access control | Slack, 6 of 6 judges | ||
| Retention, discovery & co-determination | Slack, 6 of 6 judges | ||
| Deployment & data custody | Slack, 2 of 6 judges | ||
| Integrations & extensibility | Slack, 5 of 6 judges | ||
| European sovereignty | Slack, 6 of 6 judges | ||
| Pricing transparency | Microsoft Teams (Chat), 3 of 6 judges |
Stars show the bench average per criterion; the lean counts which product each judge scored higher. Open a judge's tab for their reasoning on both sides.
Sovereignty, side by side
| Dimension | Microsoft Teams (Chat) | Slack |
|---|---|---|
| Legal entity | Not determined | Not determined |
| Ownership | Not determined | Not determined |
| Data residency | Not determined | Not determined |
| Subprocessors | Not determined | Not determined |
Facts, side by side
Only facts both products carry under the same definition — anything else would not be a fair row.