Microsoft Teams vs Slack

Pick Slack if your team lives in a multi-tool stack and needs the AI to do more than read messages—50 tools means it can post, search archives, manage channels, and hook into workflows. Pick Teams if you're already locked into Microsoft 365 and want one fewer OAuth dance; the 28-tool surface covers core messaging but leans on the rest of the Office suite for heavy lifting. For most startups and product teams, Slack wins on flexibility—more API surface, more third-party MCP servers in the wild, more examples to copy-paste. If you're in a regulated enterprise where IT already mandated Teams, the integration is simpler to get approved and the tool gap matters less because your workflows route through SharePoint and Outlook anyway. Switching from Teams to Slack after you've wired up automations costs about a week of re-mapping channels and bot permissions; going the other direction adds another few days fighting Microsoft's app registration maze.