The two dominant team messaging platforms. Which one should your company use?
SL
Slack
VS
MS
Teams
Bottom line: Slack wins on user experience, integrations, and developer ecosystem. Microsoft Teams wins on cost (included in M365 licenses), Office integration, and enterprise compliance. If your company already uses Microsoft 365, Teams is the pragmatic choice. If you're a tech-forward startup or want the best messaging experience, pay for Slack.
Our Pick Slack for UX/startups · Teams for Microsoft shops
Feature Comparison
Feature
Slack
Microsoft Teams
User experience
Excellent Win
Good
App integrations
2,500+ apps Win
700+ apps
Microsoft 365 integration
~ Basic
Native Win
Video calling
✓ Huddles
Full-featured Win
Cost (existing M365)
$7.25+/user/mo
Included free Win
Message search
✓ Excellent
✓ Good
Threads
Best-in-class Win
Good
File storage
5GB free
1TB via SharePoint Win
Compliance/security
✓ Enterprise Grid
Advanced (M365) Win
Free tier message history
90 days
Unlimited Win
Pricing Comparison
SL
Slack Pricing
Free$0/mo
Pro$7.25/user/mo
Business+$12.50/user/mo
Enterprise GridCustom
MS
Teams Pricing
Free$0/mo
Essentials$4/user/mo
M365 Business Basic$6/user/mo
M365 Business Standard$12.50/user/mo
Pros and Cons
SL
Slack
Pros
+ Superior user experience and design
+ 2,500+ app integrations
+ Best threading in messaging apps
+ Preferred by tech companies and startups
+ Slack Connect for external comms
Cons
− Free tier limits message history to 90 days
− More expensive than Teams for most orgs
− Video calling less capable than Teams
MS
Microsoft Teams
Pros
+ Free with Microsoft 365 subscriptions
+ Deep Office, SharePoint, Outlook integration
+ 1TB file storage via SharePoint
+ Excellent video meetings and webinars
+ Unlimited message history on free tier
Cons
− Clunkier interface than Slack
− Fewer third-party app integrations
− Can feel slow and bloated
Detailed Analysis
The Microsoft Tax Argument
Most enterprises already pay for Microsoft 365. Teams is included at no extra cost. Switching to Slack at $7.25-$12.50/user/month on top of an existing M365 subscription is a hard sell — unless the productivity gains are clearly measurable. For organizations of 100+ people, the cost difference adds up to tens of thousands of dollars annually.
The Developer/Startup Case for Slack
Slack's 2,500+ integrations make it the center of a developer's workflow in a way Teams can't match. GitHub notifications, PagerDuty alerts, Datadog monitors — all in Slack. The customization and automation via Slack Workflows is genuinely powerful. For tech-forward companies, Slack isn't just a chat app, it's the operational nerve center.
The honest verdict: If you're already in Microsoft 365, Teams is good enough and free. If you're choosing from scratch, Slack's experience advantage is worth the price for teams where communication quality drives output.
Best For...
Microsoft 365 shops
Teams
Already paid for, Office integration excellent
Tech startups
Slack
Best integrations, best developer experience
Video meetings
Teams
More powerful meeting and webinar features
User experience
Slack
Cleaner, faster, more enjoyable to use
Large enterprises
Teams
Compliance, admin, and M365 ecosystem
External channels
Slack
Slack Connect for client communication
Try Both Free
Both have free tiers. Your existing tools may make the choice obvious.
Slack has a better user experience and more integrations. Teams is better if you're already using Microsoft 365 — it's included at no extra cost and deeply integrates with Office apps, SharePoint, and Outlook.
Slack Pro is $7.25/user/month (billed annually), Business+ is $12.50/user/month. Enterprise Grid pricing is custom. The free tier allows unlimited users but limits message history to 90 days.
Yes. Teams has a free tier with unlimited chat, 60-minute meetings, 5GB file storage, and unlimited message history. It's also included in all Microsoft 365 Business and Enterprise plans.