Most teams end up on one of two platforms for daily chat: Slack or Microsoft Teams. They look similar — channels, messages, calls, file sharing — but they come from opposite worlds. Slack is a focused messaging app that grew outward into a platform; Teams is part of the sprawling Microsoft 365 suite. That difference shapes which one fits your team.
There's no universal winner. The right pick depends mostly on the tools you already use and how much you value integrations versus an all-in-one bundle. Here's an honest comparison for 2026 — including a major change that's reshaped the math.
The quick verdict
| If your team… | Pick | Why |
|---|---|---|
| Lives in Microsoft 365 / Office | Teams | Deep Office integration, included video meetings |
| Wants the best integrations and a slick chat experience | Slack | Huge app ecosystem, bundled AI, developer-friendly |
| Just needs free chat with full history | Teams (free) | Unlimited message history on the free tier |
The big 2026 change: Teams is no longer "free with Office"
For years, Teams' killer advantage was simple: if you paid for Microsoft 365, you already had it. That changed. Microsoft unbundled Teams from Microsoft 365 (a shift that began rolling out globally in late 2025), so Teams is now generally sold as a separate add-on rather than automatically included.
Why it matters: the old "it's basically free for us already" argument is weaker now. If you're comparing costs, check whether your plan still includes Teams or whether it's a separate line item. Always confirm current terms on the official pages — Microsoft Teams and Slack.
Free plans: Teams pulls ahead on history
Both have free tiers, and the most important difference is message history:
- Microsoft Teams' free plan offers unlimited message history.
- Slack's free plan limits searchable history to the most recent 90 days — older messages are still there but not searchable without upgrading.
If your team relies on searching old conversations and you don't want to pay, Teams' free tier has a real edge. Slack's free plan is still excellent for active, in-the-moment collaboration, with unlimited channels and a generous app ecosystem.
Pricing: it depends on size and AI needs
Paid pricing for both lands in a similar per-user, per-month range, with several plans adjusting prices in 2026 — so treat specific figures as something to verify. The general picture:
- For very small teams, Microsoft's entry-level tiers tend to be the cheapest paid option.
- Slack's paid plans cost a bit more but bundle Slack AI (channel and thread summaries, AI search) at no extra charge.
- Microsoft's AI assistant, Copilot, is typically a separate paid add-on rather than included.
So "which is cheaper" genuinely depends on your team size and whether you want AI features. Confirm the current numbers before deciding.
Integrations: Slack's traditional strength
Slack built its reputation on connecting to everything — a massive directory of third-party apps and a developer-friendly platform that makes it the hub many tech and product teams run their day from. If your workflow spans many SaaS tools, Slack usually wires them together more smoothly.
Teams integrates deeply too, but its center of gravity is Microsoft's own ecosystem — Office, SharePoint, Outlook, OneDrive. If your company already lives there, that tight integration is a genuine advantage.
Either way, a chat tool is also a great place to plug in automation so routine updates post themselves — see how to automate repetitive tasks without code and our Zapier vs Make vs n8n comparison for the connectors that do it.
Meetings and the everyday feel
Teams has strong built-in video meetings and is often the default for company-wide calls, especially in Microsoft shops. Slack offers calls and huddles and leans on integrations (and its own video features) but is most loved as a fast, focused messaging experience.
Honestly, both are capable; the "feel" differences come down to taste and what your team is used to. And whichever you choose, the bigger productivity question is managing notifications so chat doesn't become a constant interruption — that's the real cost of context switching.
So which should you choose?
- Choose Microsoft Teams if your company already runs on Microsoft 365, you want included video meetings, or you need full message history on a free plan.
- Choose Slack if you value the deepest third-party integrations, a polished chat experience, included AI, and a developer-friendly platform.
Many organizations don't get a real choice — they go with whatever their IT/ecosystem dictates. If you do have a choice, pick based on where your work already happens.
FAQ
Is Microsoft Teams still free with Microsoft 365? Not automatically anymore. Microsoft began unbundling Teams from Microsoft 365 globally in late 2025, so it's now often sold as a separate add-on. Check whether your specific plan still includes it.
Which has the better free plan, Slack or Teams? It depends on what you need. Teams' free plan offers unlimited message history, while Slack's free plan limits searchable history to 90 days. For free, searchable archives, Teams has the edge; for active collaboration and integrations, Slack is excellent.
Does Slack or Teams include AI? Slack bundles Slack AI (summaries and AI search) into its paid plans at no extra cost. Microsoft's Copilot is typically a separate paid add-on rather than included, so factor that into any cost comparison.
Which is better for integrations? Slack is traditionally stronger for third-party app integrations and developer workflows. Teams integrates most deeply with Microsoft's own ecosystem (Office, SharePoint, Outlook). The best choice depends on which tools you already use.
Can I use both Slack and Teams? Yes, and some organizations do — for example, Teams for company-wide meetings and Slack for team or project collaboration. It adds some overhead, so most teams eventually standardize on one as their primary hub.
The bottom line
Slack and Teams are both excellent; the decision is mostly about ecosystem fit. If you live in Microsoft 365, Teams is the pragmatic default — just remember it may now be a separate cost. If you want the richest integrations, bundled AI, and the smoothest chat experience, Slack still leads. Pick the one that matches where your team already works, set up your notifications sanely, and the tool fades into the background — exactly what good team chat should do.
