Slack and Microsoft Teams dominate workplace communication — together they account for most enterprise messaging worldwide. Both have added substantial AI capabilities in 2026, which changes the comparison significantly. Here’s what actually matters when choosing between them.
Quick Verdict
Slack wins for teams that prioritize communication quality, developer integrations, and a tool-first culture. Microsoft Teams wins for organizations already on Microsoft 365 — the integration with Outlook, SharePoint, Word, and Excel is unmatched.
AI Features (2026)
Slack AI
Slack AI (launched fully in 2024, mature in 2026) provides channel summaries, thread summaries, and a search assistant that can answer questions about your Slack history in plain English. “What did we decide about the Q3 launch?” — Slack AI answers from your message history. It’s genuinely useful for keeping up with busy channels. Slack AI costs an additional $10/user/month on top of your Slack plan.
Microsoft Copilot in Teams
Microsoft Copilot in Teams (part of Microsoft 365 Copilot at $30/user/month) summarizes meetings you missed, transcribes calls in real-time, suggests replies, and can answer “What action items came out of the 3pm call?” It also connects to your full Microsoft 365 context — your emails, documents, and calendar. The depth of integration across the entire Microsoft suite gives Teams AI an edge for organizations deep in the Microsoft ecosystem.
Feature Comparison
Messaging Experience
Slack wins. The messaging experience in Slack — threads, reactions, rich formatting, custom emoji, Huddles (lightweight audio/video) — is simply more pleasant to use. Teams’ messaging has improved significantly but still feels more corporate and less fluid. Most users who’ve used both prefer Slack’s communication UX.
Video Calls and Meetings
Microsoft Teams wins. Teams was built for meetings as a primary feature. Meeting rooms, breakout rooms, live captions, Together Mode, and the full-featured meeting scheduler (native to Outlook) are all more polished than Slack’s Huddles. For organizations that live in meetings, Teams’ meeting infrastructure is superior.
Integrations
Slack wins for third-party integrations. Slack has 2,500+ app integrations — GitHub, Jira, Salesforce, PagerDuty, and almost every SaaS tool has a native Slack integration. For developer and product teams using many different tools, Slack is the better hub.
Teams wins for Microsoft integrations — SharePoint, OneNote, Planner, and the full Microsoft 365 suite are seamlessly embedded. If your files live in OneDrive and SharePoint, Teams’ file management is dramatically better.
Pricing (2026)
Slack:
Free: 90-day message history, limited integrations
Pro: $8.75/user/month
Business+: $15/user/month
Enterprise Grid: Custom
+ Slack AI: $10/user/month add-on
Microsoft Teams:
Teams Essentials: $4/user/month
Microsoft 365 Business Basic: $6/user/month (includes Teams + Office web apps)
Microsoft 365 Business Standard: $12.50/user/month (includes desktop Office apps)
Microsoft 365 Copilot: +$30/user/month for AI features
Teams wins on base price — especially if you need Microsoft 365 apps anyway, you get Teams included. Slack is more expensive but includes a better pure-messaging experience.
Who Should Use Which
Choose Slack if: You’re a tech company, startup, or developer-heavy team that prioritizes messaging quality, has many SaaS tool integrations, and doesn’t rely heavily on Microsoft 365.
Choose Microsoft Teams if: Your organization already uses Microsoft 365, your files are in SharePoint/OneDrive, you run many video meetings, or you want the best price-per-seat for a communication + productivity bundle.
Verdict
This is one of the clearest “it depends on your stack” decisions in software. Microsoft Teams is the obvious choice if you’re a Microsoft shop — you’re already paying for it. Slack is the obvious choice if you’re not. For teams evaluating from scratch without Microsoft lock-in: Slack’s superior messaging experience and developer integrations make it worth the premium for most tech companies. For cost-conscious SMBs or enterprises standardizing on Microsoft: Teams provides excellent value as part of the 365 bundle.
Explore more workplace AI tool comparisons at AI Productivity Picks.