Microsoft Says Teams Has More Active Users than Slack

Microsoft Declares Success for Teams Over Slack

Teams has more daily active users than Slack (source: Microsoft)
Teams has more daily active users than Slack (source: Microsoft)

Microsoft’s July 11 post about the progress of Teams shared the assertion that Teams now has 13 million daily active users and 19 million weekly active users. Without ever saying it in text, the graph supplied by Microsoft underlined the point that Teams has surpassed the last official Slack number of “more than 10 million daily active users” in its pre-IPO S-1 filed with the SEC on April 26, 2019.

Slack September 2019 Growth

On October 10, Slack reported that the September 2019 number for daily active users had reached 12 million. More interestingly, Slack said that users of their paid service spent 9 hours daily connected to the service, 90 minutes of which were in active use generating 5 billion weekly activities (like sending a message). Slack also pointed to the 500,000 apps in their app directory as evidence of strong use of the platform. In a remark that might be a subtle dig at Teams, Slack also said that “you can’t transform a workplace if people aren’t actually using the product.” In other words, growth in user numbers is meaningless unless people actually use a platform to get real work done.

Low Number

Returning to Microsoft’s post, their not-so-subtle comparison positioning Teams ahead of Slack seems like good news, but I was surprised at just how low Microsoft’s number is. In March 2019, Microsoft said that 500,000 organizations now use Teams. That number had grown at around 40,000 organizations per month since the last data given by Microsoft, so it could be in the 600,000 – 650,000 range now, assuming that Teams maintained its recent growth rate since March.

In December, Accenture said that they had 170,000 users on Teams. We also know from Microsoft’s March statement that 150 organizations have 10,000 or more users on Teams (presumably accounts like Emirates, FedEx, Lexmark, The Adecco Group, KONE, and McCann Worldgroup as mentioned in Microsoft’s post). Taking Accenture and the 150 organizations together, that accounts for around 1.7 million users of the overall population.

Defining an Active Teams User

Not all of these users are active. There’s a big difference between an Office 365 license bought by an organization and assigned to a person and someone who actually uses Teams regularly. Or, as Microsoft calls them, qualified entitlements versus active entitlements. Office 365 has 180 million monthly active users, but that’s not nearly the total number of licensed Office 365 users.

Microsoft doesn’t define what a daily active user of Teams does, but we can assume that it’s someone who signs into Teams and does something, like contribute to a channel conversation, participate in a meeting, or have a personal or group chat. These are basic operations that don’t take other activities into account, such as working with Files, Planner, or other first-party or third-party apps integrated in Teams.

Figuring Out the Numbers

Taking the 19 million weekly active users reported by Microsoft and subtracting 1.7 million for the large organizations (more than 10,000 users), we get 17.3 million for the remaining organizations. If we divide this number by 650,000 organizations, we get an average of 27 weekly active users per organization. Taking 500,000 organizations as the yardstick, we get 35 weekly active users per organization.

These numbers seem low. They might be accounted for by:

  • Many organizations are still in test mode and haven’t proceeded to full deployment. Ancedotal evidence suggests that this is not the case as I hear of many organizations that use Teams extensively. However, it’s also true that many organizations are in the process of moving from Skype for Business Online to Teams. When these migrations are over, we should see a further increase in Teams daily active users.
  • Many small organizations use Teams (free or paid versions). We know that a large percentage of Office 365 tenants are small and have less than 50 seats, so the presence of a large percentage of small organizations in the overall count might contribute to the relatively low average number of active Teams users per organization.

In January, I thought the total Teams user base might be in the 40 million range. That figure was for licensed users based on an average of 100 users per organization (at that time, Teams reported that it was used by 420,000 organizations). Remember that Teams is part of every Office 365 plan, so everyone assigned an Office 365 E3 or E5 license (for example) is automatically a licensed Teams user unless Teams is removed from the plan. In one way, you could say that Teams has 180 million licensed users!

Of course, because Microsoft hadn’t published any firm data on Teams at that time, this was pure guesswork. But even so, I guess my figure could be in the ballpark because of the difference between active users and licensed users.

In any case, we now have a definite number to work with and can track the future growth of Teams from this baseline.


Microsoft’s post included mention of four new Teams features. One of the reasons why you need to subscribe to the Office 365 for IT Pros eBook is to stay updated with new developments. We include information about new features as soon as we see them appearing in our tenants and have a chance to figure out how they work.

4 Replies to “Microsoft Says Teams Has More Active Users than Slack”

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.