Slack vs Microsoft Teams: Which Team Chat App Should You Use?

Choose Slack if your team wants the widest app and integration catalog in this category, or needs Slack Connect to work with people outside the company. Choose Microsoft Teams if your organization already runs on Microsoft 365 and you want chat, video meetings and file co-editing in one app tied to Outlook. Both are hosted by their vendors and closed source, so the choice comes down to the software you already use and what the paid plans cost as the team grows, and the Microsoft Teams vs Slack comparison sets the two side by side.

Quick comparison

The table uses the product listings and the team chat ranking, which weighs features and integrations first, then hosting choice, price and open-source status. For how the scores are set, see how the rankings work.

	Slack	Microsoft Teams
Made by	Slack	Microsoft
Price model and free plan	Free plan with 90 days of message history; paid plans per user	Free version with limits; fuller features in Microsoft 365 business plans
Platforms	Web, Windows, macOS, Linux, iOS, Android	Web, Windows, macOS, iOS, Android
Hosting	Hosted by Slack	Hosted by Microsoft; cannot be self-hosted
Open source	No	No
Where data is stored or key design difference	Channels, direct messages and the widest app catalog in the ranking	Chat, meetings and shared files inside Microsoft 365 and Outlook
Best for	Teams that want the largest app ecosystem	Organizations already standardized on Microsoft 365

Pricing and free plans

Slack's free plan has no time limit on use and keeps 90 days of message history. Paid plans add longer history and more administration, and they are priced per user per month. The Slack listing notes that its free plan never expires, and that cost rises per user as a team grows.

Teams has a free version with limits, and its listing does not spell those limits out, so check them on Microsoft's site. Its fuller features come with Microsoft 365 business plans. A team on a business plan may already have Teams in its subscription, which changes the cost comparison.

For a small team, the history limit is often the deciding difference. Slack's free plan shows 90 days, while Pumble lists unlimited message history on its free plan, and Zoho Cliq offers a free chat plan for teams of any size. Slack's paid plans scale with headcount, so run the numbers for your team size with the subscription cost calculator before you commit.

Platforms and sync

Slack runs on the web and on Windows, macOS, Linux, iOS and Android. It organizes conversations into channels and direct messages, and it adds huddles for audio and video, clips for recording updates, and lists and canvases for projects and documents.

Teams runs on the web and on Windows, macOS, iOS and Android. Its listing does not include Linux, so a team with Linux desktops should check that gap before choosing it.

Teams combines chat, meetings and files. Documents open and co-edit from inside a channel, and meetings link to Outlook calendars. The ranking calls it heavier than single-purpose chat tools such as Slack or Zulip, which matters if your team wants a lighter client.

Features that set them apart

• App catalog. Slack has the widest app and integration catalog in the ranking. Teams' integrations center on Microsoft 365, including Outlook, shared documents and meetings.
• Outside partners. Slack Connect works with people outside your company. The Teams listings do not describe an equivalent, so check Teams' external access settings before you plan a partner workflow.
• Meetings. Teams includes video meetings tied to Outlook calendars. Slack has huddles for audio and video and clips for recorded updates.
• Project work. Slack's lists and canvases cover project tracking and documents inside the workspace. Teams' co-editing works on the shared files that sit in its channels.
• Free plan terms. Slack's free plan never expires, but it keeps only 90 days of history. Teams' free version has limits that the listing does not spell out.

Privacy, openness and data ownership

Both products are closed source, so their code cannot be inspected. The ranking places Slack in the vendor-cloud group, and the Teams listing says it cannot be self-hosted. Both products therefore keep your conversations on the vendor's infrastructure.

If you need chat servers under your own control, the ranking's self-hostable options are Zulip, Mattermost and Rocket.Chat. Each of them can run on your own servers, though an IT team has to run them.

Neither listing states where conversation data is stored, so read each vendor's data and admin terms before you move sensitive discussions into it.

Who should choose Slack

• Your team relies on many outside tools and wants integrations in one place.
• You work with clients, vendors or partners outside your company and want Slack Connect.
• You are a small team that can live with 90 days of history on the free plan.
• You do not already run on Microsoft 365.
• You want huddles and clips alongside chat.

Other choices are in Slack alternatives.

Who should choose Microsoft Teams

• Your organization already has Microsoft 365 business plans and uses Outlook calendars.
• You want chat, video meetings and co-editing in one app.
• You want a free version to start, and a route to fuller features through a Microsoft 365 plan.
• Your team does not need a Linux desktop app.

Other choices are in Microsoft Teams alternatives.

Other options worth a look

• Zulip: open source under Apache-2.0, with apps for major desktop and phone systems and a free Standard plan for eligible organizations. You can self-host it or use Zulip Cloud. See Slack vs Zulip.
• Mattermost: self-hosted team chat with source under AGPL-3.0, for teams that must keep chat on their own servers. Its Enterprise editions are paid. See Mattermost vs Slack.
• Zoho Cliq: a free chat plan for teams of any size, hosted by Zoho, with a smaller app catalog than Slack. See Microsoft Teams vs Zoho Cliq.
• Pumble: a free plan with unlimited users and message history. Paid plans are priced per seat and add group meetings.

Related rankings and guides

• Best team chat software: the full ranking, with hosting and open-source notes.
• How to choose team chat software: what to check before you pick a tool.
• How to choose a messaging app: for chat beyond the workplace.
• Best apps for remote teams: other tools that work alongside chat.
• Communication software: video, email and whiteboard tools.
• Microsoft Teams vs Slack: the full comparison page.