Slack vs Microsoft Teams: The Real Differences in 2026
Microsoft Teams overtook Slack in total user count years ago, mostly because it ships free inside Microsoft 365 subscriptions that companies already pay for. But "more users" doesn't mean "better tool" — the two remain meaningfully different to actually work in.
Day-to-Day Usability
Slack's channel-based design, lightweight threads, and fast search have made it the benchmark every competitor gets compared against. Messages feel ephemeral and conversational; finding an old message or file is usually a few keystrokes away. Teams has improved significantly, but its interface still carries the weight of being one tile in the larger Microsoft 365 app grid — switching between Chat, Teams, and Calendar feels more like navigating an OS than chatting with a colleague.
Integrations
Slack's App Directory remains the deepest third-party ecosystem in workplace chat — thousands of integrations, many built by the tool vendors themselves (GitHub, Salesforce, Notion, Zapier) rather than community ports. Teams integrates excellently with Microsoft 365 (SharePoint, Planner, Office apps) but third-party integrations outside the Microsoft ecosystem are noticeably thinner.
If your stack is mostly non-Microsoft tools, Slack's integrations will feel native. If you live in Microsoft 365, Teams' integration is unbeatable specifically there.
Video and Meetings
Teams has the edge here, unsurprisingly — it's effectively Microsoft's full meeting platform (the old Skype for Business lineage) wrapped into a chat client, supporting large webinars, breakout rooms, and live captions natively. Slack's huddles are great for quick, low-friction calls but were never built to replace a dedicated meeting platform like Zoom or Teams for large, formal meetings.
Pricing and Bundling
This is where the comparison gets unfair: Teams is included free with Microsoft 365 Business Basic (~$6/user/month), which most enterprises already pay for. Slack's comparable paid tier (Pro) costs roughly $7.25/user/month on top of whatever messaging tool you'd otherwise drop. For finance teams, "Teams is free, Slack is $7/seat" is often the entire conversation.
Message History and Free Tier Limits
Slack's free tier caps message history at 90 days — a real constraint for smaller teams that can't justify a paid plan but want to search old conversations. Teams' free tier doesn't impose this specific limit, which matters for budget-constrained teams.
The Verdict
Choose Slack if you value the best day-to-day chat experience and a deep non-Microsoft integration ecosystem, and the per-seat cost is justified by IT not having to fight a poor UX.
Choose Microsoft Teams if you're already paying for Microsoft 365 — the marginal cost is effectively zero, and the meeting tooling is genuinely strong.
For greenfield decisions with no Microsoft 365 commitment, Slack still wins on pure UX. For nearly everyone else already inside the Microsoft ecosystem, Teams is the pragmatic default.
