Slack shows up at 592,832 companies in 6sense’s instant messaging and chat tracking, against 115,457 for Microsoft Teams. Microsoft measures reach in seats instead, with more than 450 million paid Microsoft 365 commercial seats disclosed in January 2026.
This guide breaks down Slack vs Teams market share by each measure, then covers Microsoft 365 overlap, monthly customer movement, country splits, 2026 pricing, the EU’s Teams commitments and AI add-on adoption.
Slack vs Teams Market Share
What Is the Slack vs Teams Market Share in 2026?
Slack holds a 16.70% share of the Instant Messaging and Chat category in 6sense’s technographic data, as of October 2026. Microsoft Teams holds 3.25% and ranks 5th, three places behind Slack.
6sense counts companies whose technology use it detects, not seats or daily users. It puts Slack’s lead at 477,375 companies.
Neither tool tops the category. G Suite, now sold as Google Workspace, holds 55.84% across 1,982,081 domains.
| Tool | Domains tracked | Estimated market share |
|---|---|---|
| G Suite | 1,982,081 | 55.84% |
| Slack | 592,832 | 16.70% |
| Zendesk | 180,414 | 5.08% |
| Intercom | 161,360 | 4.55% |
| Microsoft Teams | 115,457 | 3.25% |
| Tidio | 67,434 | 1.90% |
Source: 6sense Technographics, Instant Messaging and Chat category, October 2026
450 Million-Plus Seats: How Microsoft Counts Teams Reach
Microsoft reported more than 450 million paid Microsoft 365 commercial seats on its January 28, 2026 earnings call, with seat growth of 6% year over year. It remains the latest seat total Microsoft has disclosed.
Source: Microsoft FY26 Q2 earnings call, January 28, 2026
That total covers the whole Microsoft 365 commercial base, not Teams users alone. The earnings materials cited here give no Teams-only seat count, so the wider Microsoft 365 base is the closest official proxy.
Seats and company counts measure different things. One large company can hold thousands of seats yet appears once in a company count.
Microsoft 365 Customers Who Also Run Slack
Okta’s Businesses at Work 2026 report found that 42% of its Microsoft 365 customers also deploy Slack. AWS and Google Workspace each reach 51%, Zoom 48% and Salesforce 47%.
The same report ranks Slack 6th among business apps by customer count worldwide and 4th in Japan.
Data covers the Okta Integration Network from November 1, 2024 to October 31, 2025. Okta notes that its Microsoft 365 customers may differ from those on other identity platforms.
Source: Okta, Businesses at Work 2026 (published April 30, 2026; data November 2024 to October 2025)
Is Slack Losing Customers to Teams?
6sense does not record where lost customers go, so its data cannot confirm direct switching. It does publish monthly additions and losses for each tool.
For the month shown in October 2026, Teams added 1,469 customers and lost 234. Slack added 1,384 and lost 428.
Teams posted more additions from a smaller tracked base of 115,457 companies, compared with 592,832 for Slack.
Source: 6sense Technographics, Slack vs Microsoft Teams customer movements, October 2026
Slack vs Teams Market Share by Country and Company Size
Customers in the United States, United Kingdom and Canada
| Country | Slack customers | Slack share | Teams customers | Teams share |
|---|---|---|---|---|
| United States | 319,190 | 66.20% | 49,138 | 54.98% |
| United Kingdom | 41,414 | 8.59% | 10,501 | 11.75% |
| Canada | 26,768 | 5.55% | 6,285 | 7.03% |
Source: 6sense Technographics, customers by geography, October 2026
The United States accounts for 66.20% of Slack’s customers and 54.98% of Teams’ customers. The United Kingdom and Canada each carry a larger share of Teams’ base than of Slack’s.
Company Size and Industry
Slack’s largest group is companies with 20 to 49 employees, at 204,121. Firms with 100 to 249 employees (144,316) and 0 to 9 employees (92,916) follow.
Teams’ largest band is 100 to 249 employees, at 26,797 companies. Next are 20 to 49 employees (19,753) and 1,000 to 4,999 employees (15,888).
By industry, Marketing (10,338), Digital Marketing (8,135) and Social Media (7,461) lead for Slack. Project Management (1,867), Education (1,746) and Managed Services (1,503) lead for Teams.
Source: 6sense Technographics, customers by employee size and industry, October 2026
How Much Do Slack and Teams Cost in 2026?
Microsoft Teams Essentials lists at $4.00 per user per month, paid yearly, on Microsoft’s US site. Microsoft 365 Business Basic, which bundles Teams with business email, lists at $7.00.
Source: Microsoft, Compare Microsoft Teams business options, October 2026
Slack Pro costs $7.25 per user per month on annual billing. Ongoing Slackbot access is limited to Business+ and Enterprise+, per Slack’s pricing page.
| Slack plan | Annual billing (per user/month) | Monthly billing (per user/month) |
|---|---|---|
| Free | 0 | 0 |
| Pro | 7.25 | 8.75 |
| Business+ | 15.00 | 18.00 |
| Enterprise+ | Contact sales | Contact sales |
Source: Slack pricing page, October 2026
The EU’s Seven-Year Teams Commitments
The European Commission made Microsoft’s Teams commitments binding on September 12, 2025, closing a case that began with a 2020 complaint from Slack.
Microsoft must offer suites without Teams at a reduced price and publish interoperability and data portability information. After a market test, it also widened the price gap between suites with and without Teams.
| Date | Step |
|---|---|
| 2020 | Slack files complaint with the Commission |
| July 27, 2023 | Commission opens formal investigation |
| June 25, 2024 | Statement of objections sent to Microsoft |
| May 16 to June 16, 2025 | Market test of proposed commitments |
| September 12, 2025 | Commitments made binding |
| Seven years from decision | Most commitments stay in force |
| Ten years from decision | Interoperability and data portability terms stay in force |
Source: European Commission, decision on Microsoft Teams commitments, September 12, 2025
The Commission also noted Microsoft’s decision to align its worldwide suite offers and pricing with these terms. No source cited here measures the effect on Slack or Teams adoption.
30 Million Copilot Seats and 150% Slackbot Growth in 2026
Paid Microsoft 365 Copilot seats rose from 15 million in January 2026 to 20 million in April and more than 30 million in the July 29, 2026 results.
Microsoft said net seat additions more than doubled quarter over quarter in that last period. These are paid business seats, separate from consumer chatbot user counts.
Source: Microsoft earnings calls (January 28 and April 29, 2026) and FY26 Q4 earnings release (July 29, 2026)
Salesforce reported Slackbot users up more than 150% quarter over quarter in fiscal Q2 2027, which ended July 31, 2026. It also counted 7.0 billion Agentic Work Units delivered to date across Agentforce and Slack.
Source: Salesforce, Q2 fiscal 2027 results, August 26, 2026
Paid seats and user growth are different measures. The two products cannot be ranked on these figures.
Revenue Context for Slack vs Teams Market Share
Microsoft’s Productivity and Business Processes segment earned $37.8 billion in the quarter ended June 30, 2026, up 14%. The segment holds Microsoft 365, which includes Teams, plus LinkedIn and Dynamics 365.
Within it, Microsoft 365 Commercial cloud revenue grew 14% on a reported basis. The release does not split out Teams revenue.
Source: Microsoft FY26 Q4 earnings release, July 29, 2026
Salesforce’s Q2 fiscal 2027 highlights give no Slack revenue line. They report Slack’s fastest quarterly Net New Annual Order Value growth since Salesforce acquired Slack.
Total Salesforce revenue reached $11.3 billion in that quarter, up 11%. The company raised fiscal 2027 revenue guidance to $46.1 billion to $46.4 billion.
Source: Salesforce, Q2 fiscal 2027 results, August 26, 2026
Microsoft’s next report, for fiscal Q1 2027, is scheduled for October 28, 2026.
Source: Microsoft earnings date announcement, October 7, 2026
FAQs
Is Slack bigger than Microsoft Teams?
By company count, yes. 6sense detects Slack at 592,832 companies and Teams at 115,457 in October 2026. By seats, Microsoft reports more than 450 million paid Microsoft 365 commercial seats, a total that covers more than Teams.
What percentage of the chat market does Slack hold?
16.70% of the Instant Messaging and Chat category tracked by 6sense, as of October 2026. That ranks Slack 2nd behind G Suite at 55.84%, with Microsoft Teams 5th at 3.25%.
Is Slack more expensive than Teams?
On list price, yes. Slack Pro costs $7.25 per user per month billed annually. Microsoft Teams Essentials costs $4.00 and Microsoft 365 Business Basic $7.00, based on October 2026 pricing pages.
Do companies use Slack and Teams together?
Okta’s Businesses at Work 2026 report found 42% of its Microsoft 365 customers also deploy Slack. The data runs from November 2024 to October 2025 and covers Okta customers only.
Is Reddit a reliable source for Slack vs Teams market share?
No. Reddit threads reflect individual opinions, not measured adoption. Tracked data from 6sense, Okta and Microsoft earnings releases gives dated, sourced figures for each tool.
References
https://www.6sense.com/tech/instant-messaging-chat/slack-vs-microsoftteams
https://www.okta.com/ja-jp/newsroom/press-releases/okta-businesses-at-work2026/
https://microsoft.com/en-us/investor/earnings/fy-2026-q4/press-release-webcast
