Independent comparison for enterprise buyers. Updated May 2026.
Quick verdict: Choose Slack when channel-led messaging quality, a deep third-party app ecosystem, and developer-friendly workflows are decisive, or when teams already operate around external partner channels through Slack Connect. Choose Microsoft Teams when your organisation is standardised on Microsoft 365, when meetings and voice are core requirements alongside chat, or when commercial bundling with E3 or E5 licences makes incremental cost effectively zero. The differentiator is scope: Slack is a focused messaging and workflow product; Teams is a unified hub for chat, meetings, voice, and Microsoft 365 collaboration.
| Criteria | Slack | Microsoft Teams |
|---|---|---|
| Rating | 4.5 / 5.0 (32,000 reviews) | 4.4 / 5.0 (28,000 reviews) |
| Deployment | Cloud (SaaS) | Cloud (SaaS), on-prem voice options |
| Pricing Model | Per-user subscription | Per-user, bundled in Microsoft 365 |
| Best For | Tech-led teams, partner collaboration | Microsoft 365 estates, meetings-first |
| Meetings | Native huddles, Slack calls | Full meeting suite, voice, webinars |
| App Ecosystem | 2,600+ third-party apps | Microsoft 365 + 2,000+ apps |
| Key Strength | Channel UX, integrations, Slack Connect | Microsoft 365 integration, meetings, voice |
| Key Limitation | No native voice/PBX, separate cost | Channel UX, notification fatigue |
| AI | Slack AI, agentic Slack | Microsoft 365 Copilot in Teams |
| Ownership | Salesforce | Microsoft |
Slack and Microsoft Teams are the two dominant enterprise collaboration platforms in the global market. Both products combine persistent chat, group channels, file sharing, meetings, and an integration layer for third-party applications. The two products approach the category from different starting points and accumulate different strengths as a result.
Slack is a focused messaging product. The channel-based information model, the search experience, the keyboard-driven user interface, and the third-party app marketplace are widely regarded by reference customers as the strongest in the category for text-led collaboration. Slack Connect lets organisations share dedicated channels with external partners, customers, and suppliers, which has become a core differentiator for firms with significant external collaboration needs. Slack AI provides conversation summaries, daily recaps, and channel search; Salesforce-led agentic Slack pushes the platform towards orchestrating action across connected systems.
Microsoft Teams is a unified hub. Chat, channels, meetings, voice, webinars, screen sharing, file collaboration in SharePoint and OneDrive, and embedded Microsoft 365 apps are delivered through a single client. Teams Phone provides full cloud PBX functionality. Teams Rooms covers video conferencing hardware. Microsoft 365 Copilot is now embedded in Teams chat, meetings, and channels, providing meeting recaps, action item extraction, and content drafting.
On meetings, Teams is the stronger product for organisations whose primary collaboration mode is meetings and voice. Slack's huddles cover lightweight audio and screen sharing; for full meetings, recordings, transcription, and breakout rooms most Slack customers bring a separate product, often Zoom.
On integrations, Slack's app directory is the larger third-party ecosystem; Teams has narrower third-party app depth but tighter integration with the Microsoft 365 estate including Outlook, SharePoint, Power Platform, and Dynamics 365. The right answer typically tracks the buyer's broader Microsoft commitment.
Slack pricing is per user per month: Pro at $7.25, Business+ at $12.50, Enterprise Grid at custom pricing typically $15-30 per user per month at enterprise volumes. Annual contract values for global enterprises typically land at $500K to $5M+. Slack AI is an additional per-user add-on.
Microsoft Teams is bundled into Microsoft 365 E1, E3, and E5 licences. For organisations already on Microsoft 365, Teams incremental cost is effectively zero. Standalone Teams Essentials is $4 per user per month. Microsoft 365 E3 is $36, E5 is $57. Teams Phone adds approximately $8 per user per month. Microsoft 365 Copilot is an additional $30 per user per month. For a 5,000-seat enterprise already on E3, adding Slack is a real incremental spend of $400K to $750K per year; staying on Teams is effectively no new line item.
Choose Slack when channel-led messaging quality and search are decisive, when external partner and customer collaboration through Slack Connect aligns with how teams work, when third-party integrations from the Slack app directory are core to workflows, when your organisation has a strong engineering or developer culture, or when you are not standardised on Microsoft 365.
Choose Microsoft Teams when your organisation is standardised on Microsoft 365 and bundling economics are decisive, when meetings and voice are core collaboration requirements alongside chat, when integration with SharePoint, Outlook, and the Microsoft 365 estate is operational, or when Microsoft 365 Copilot is part of your AI strategy.