Slack vs Microsoft Teams: Complete Cost Comparison for 2026
An honest, vendor-neutral comparison of Slack and Teams pricing, features, and total cost of ownership. Including the AI cost angle that most comparison pages miss.
Teams wins on base price
If you already have Microsoft 365, Teams is free. Even standalone, Teams Essentials ($4/user/mo) undercuts Slack Pro ($8.75/user/mo) by more than half.
Slack wins on AI cost
Slack AI is free on paid plans. Microsoft Copilot is $18-21/user/month extra. For 100 users, that is $21,600-$25,200/year in AI costs that Slack does not charge.
Price Comparison
| Feature | Slack | Microsoft Teams |
|---|---|---|
| Entry price | $8.75/user/mo | $4/user/mo (Essentials) |
| Comparable tier | Pro: $8.75/user/mo | Business Basic: $6/user/mo |
| Enterprise tier | Grid: $15-25/user/mo | E3/E5: $36-57/user/mo |
| AI features | Included free (paid plans) | Copilot: +$18-21/user/mo |
| Message history | Unlimited (paid) | Unlimited |
| Integrations | 2,600+ | 700+ |
| Video calls | Huddles (50 people) | Up to 300 people |
| Screen sharing | In huddles | In meetings + channels |
| File storage | 10-20 GB/user | 1 TB/user (M365) |
| SSO | Business+ ($12.50+) | All paid plans |
| Compliance/DLP | Business+ or Enterprise | E3/E5 plans |
| Workflow automation | Workflow Builder | Power Automate |
| External collaboration | Slack Connect | External access/guests |
| Developer ecosystem | Strong (Bolt SDK) | Growing (Teams Toolkit) |
| Desktop app | Electron (lighter) | Electron (heavier) |
| Mobile app | Excellent | Good |
The M365 Bundle Effect (the "Slack Tax")
If you already pay for Microsoft 365, Teams is included at no extra cost. Adding Slack on top creates a "Slack tax" of $8.75 to $15 per user per month.
| Team size | Slack Pro annual cost | Teams cost (M365 shop) | Slack tax |
|---|---|---|---|
| 50 users | $4,350 | $0 | $4,350/yr |
| 100 users | $8,700 | $0 | $8,700/yr |
| 200 users | $17,400 | $0 | $17,400/yr |
| 500 users | $43,500 | $0 | $43,500/yr |
AI Feature Comparison
This is the biggest pricing reversal in the Slack vs Teams comparison. Since June 2025, Slack AI is free on all paid plans. Microsoft Copilot costs $18-21/user/month extra.
| Team size | Slack AI (annual) | Copilot (annual, $19.50 avg) | Slack saves |
|---|---|---|---|
| 50 users | $0 | $11,700 | $11,700/yr |
| 100 users | $0 | $23,400 | $23,400/yr |
| 200 users | $0 | $46,800 | $46,800/yr |
| 500 users | $0 | $117,000 | $117,000/yr |
Teams Price Increase Alert
Microsoft is raising Business Basic from $6 to $7 per user per month in July 2026, a 16.7% increase. This narrows the base price gap with Slack Pro ($8.75/user/month monthly, $7.25 annual). Factor this increase into your comparison if evaluating Teams for the long term.
When Slack Wins, When Teams Wins
Choose Slack if...
- You need 2,600+ integrations (especially developer tools)
- AI features are important and you want them included in the price
- You use Slack Connect for external partners/clients
- Your team prefers Slack's channel-based communication model
- Developer workflows (GitHub, Jira, CI/CD) are central to your work
Choose Teams if...
- You already have Microsoft 365 (Teams is free)
- You need large video meetings (300 participants vs 50)
- Deep SharePoint/OneDrive integration is important
- Budget is the primary driver and AI is optional
- Your company is already standardised on Microsoft tools
Frequently Asked Questions
Is Microsoft Teams cheaper than Slack?
It depends on your existing stack. If you already have Microsoft 365, Teams is included at no additional cost, making it significantly cheaper. If you are starting fresh, Teams Essentials costs $4/user/month versus Slack Pro at $8.75/user/month. However, Slack includes AI features free on paid plans, while Microsoft Copilot costs $18-21/user/month extra. For AI-heavy teams, Slack can be the cheaper option overall.
Should I switch from Slack to Teams to save money?
Switching tools is expensive in hidden ways: migration effort, lost message history, retraining, broken integrations, and productivity dips during transition. If your annual Slack spend is under $50,000, the switching costs may exceed the savings. Only consider switching if the savings are substantial (typically $30,000+ per year) and you already have M365 for other reasons.
Which has better AI features, Slack or Teams?
Both have strong AI capabilities, but the pricing models differ dramatically. Slack bundles AI into all paid plans at no extra cost since June 2025. Microsoft requires Copilot as a paid add-on at $18-21 per user per month on top of M365. Feature-wise, Copilot is more capable (it spans the entire M365 suite), but Slack AI is improving rapidly and covers the core use cases: summaries, search, huddle notes.
Can I use both Slack and Teams?
Yes, many companies do. A common pattern is Teams for Microsoft-integrated collaboration (document editing, project management, video meetings) and Slack for cross-team communication and developer workflows. However, running both tools doubles your communication costs and can fragment conversations. Evaluate whether the integration benefits justify the additional expense and complexity.