For most small businesses, Slack vs Teams is decided by what you already use. If your business runs on Microsoft 365, Teams is the natural fit because it's tied into Outlook, OneDrive, SharePoint and built-in video meetings. If you don't, or you work with lots of clients and freelancers in shared channels, Slack is usually the easier and more flexible choice.
The next thing to know is that both apps do the basics well. You'll get channels, direct messages, file sharing, search and calls in either one. The real differences sit around them: how meetings work, which apps plug in, how you bring outside people in, and where your files end up living.
So rather than a feature-by-feature shootout, I'd start the Slack vs Microsoft Teams decision with a simpler question.
Start with what you already pay for
Your existing software does a lot of the deciding for you. Find the branch that matches your business.
You run on Microsoft 365
If your team already uses Outlook, Word, Excel and OneDrive, Teams is hard to argue against. Files shared in Teams are stored in SharePoint and OneDrive, meetings sit in your Outlook calendar, and everyone signs in with the account they already have. That's one less app to manage and one less place for documents to get lost.
One thing to check: in some regions Microsoft sells Teams separately from Microsoft 365 rather than bundled in. So check how it's packaged where you are before assuming it's already included in your plan.
You run on Google Workspace
If you live in Gmail, Google Drive and Google Calendar, Teams loses its home advantage. Google Workspace has its own chat and meetings, which may be enough for a small team. If you want more, Slack tends to sit comfortably alongside Google tools, with apps for Drive and Calendar so links and meeting reminders show up in your channels.
You run on neither
If your business is a mix of tools, or you're starting fresh, Slack is usually the easier pick. It doesn't assume you use a particular office suite, and its large app directory means you can connect most of the tools a small business relies on, from project boards to CRMs to form builders. Teams can still work here, but you'd be adopting part of the Microsoft world to get the most from it.
Six differences that matter day to day
- Meetings and calls. Teams has full video meetings built in, with scheduling through Outlook. That's a big plus if you run client calls or webinars. Slack has huddles, which are quick audio or video chats started from a channel or DM. They're great for a fast question, but many Slack teams still use a separate tool for scheduled meetings.
- Integrations. Slack is known for its large app directory and for being easy to connect to other software. Teams connects deeply with Microsoft products and has its own app store, but it's at its best inside the Microsoft family.
- Guests and clients. Slack Connect lets you share a channel with another company, so each side stays in its own workspace and you talk in one shared space. Teams handles outside people through external access, for chatting with other organisations, and guest access, for adding someone into your team.
- Search and history. Both have good search on paid plans. On Slack's free plan, it limits how much history you can see, so older messages and files may drop out of view. Check the current terms if your team leans on old conversations.
- File storage behind it. In Teams, files live in SharePoint and OneDrive, so they're part of your wider Microsoft storage. In Slack, files are stored in Slack itself unless you share them from a connected tool like Google Drive or Dropbox.
- Admin. Teams is managed through Microsoft 365 admin tools, which is convenient if someone already looks after your Microsoft accounts. Slack has its own admin settings, which are simpler for a small team but sit apart from your other systems. Slack is owned by Salesforce, which matters mostly if you already use Salesforce products.
Working with clients and freelancers
This is where I'd spend the most thought, because most small businesses don't only talk to their own staff. You've got freelancers, agencies, suppliers and clients, and the chat app you choose decides how easy that is.
Slack Connect is one of Slack's strongest points here. You can set up a shared channel with a client, both teams keep their own workspaces, and the conversation sits next to your internal channels. Plenty of freelancers and agencies already use Slack, so you'll often find they're set up and ready.
Teams works well when your clients are also on Microsoft 365, which is common with larger and more corporate organisations. Chatting across companies through external access feels natural there, and inviting someone in as a guest gives them access to a specific team and its files. It can feel clunkier for people who aren't Microsoft users, so think about who your clients are.
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Whichever you pick, agree some ground rules early: which channels clients can see, who invites guests, and when you take a conversation to email. If you're working with a remote team, these remote work productivity tips will help the habits stick.
If you switch, do it in this order
Moving from one chat app to another is more about people than software. Here's the order I'd follow.
- Decide why you're switching and write it down in one sentence, so everyone understands the reason.
- Check how the new app is packaged and what's included in each plan, so there are no surprises later.
- Map your current channels and remove the ones nobody uses before you recreate anything.
- Connect the apps your team relies on, like your calendar, file storage and project tool.
- Export or save anything you need to keep from the old app, and check the current terms for what can be moved.
- Tell clients and freelancers about the change, with a date and simple instructions for joining.
- Pick a switch-over day, run both apps for a short overlap, then close the old one so conversations don't split.
If you're on Teams and planning to run online events, I've also covered how to run a webinar in Microsoft Teams.
Make a team chat app? See how to get it featured on this list.
Frequently asked questions
Is Slack or Teams better for a small business?
It depends on what you already use. Teams suits businesses running on Microsoft 365. Slack suits teams that use a mix of tools or work closely with clients and freelancers in shared channels.
Is Microsoft Teams free?
There's a free version of Teams for personal and small use. In some regions Teams is sold separately from Microsoft 365, so check how it's packaged where you are.
Does Slack's free plan keep all my messages?
Slack's free plan limits how much message history you can see. Check the current terms before relying on it for anything you need to look back on.
Can I talk to people at other companies in Slack and Teams?
Yes. Slack Connect lets you share channels with other companies, and Teams offers external access for chatting with other organisations and guest access for adding outside people to a team.
