Many reasons can lead users or even companies to use several collaboration tools at the same time.
In 2025, 2 solutions are leading the market: Slack mostly used by small and/or tech companies, Microsoft Teams mostly used by larger and/or “standard” companies due to its Office365 strong link.
If It’s possible for 2 companies to connect to each other through a common channel on Slack, using Slack Connect, and Shared Channels on Teams, it’s unfortunately not natively possible for a Slack user to chat with a Teams user.
This article will guide through different methods you can set up to integrate Microsoft Teams with Slack.

Apps such as Microsoft Teams Calls for Slack

The first straightforward solution is to check the Slack and Teams marketplaces for existing apps. And a “wow” moment, there’s an official Microsoft Teams Calls app in the Slack marketplace!
Unfortunately, after a deeper look, you’ll find that this app is merely a shortcut to join Teams calls.
What about other existing apps that could integrate Slack with Microsoft Teams? After conducting a broad search, we identified the following:

On the Slack marketplace:

  • Migration apps: For moving between Slack and Microsoft Teams
  • Outlook Calendar <> Slack: Syncs status, schedules, etc.
  • Slack for Outlook: Allows sending emails from Outlook to Slack

On the Teams marketplace:

  • Migration apps (again)
  • Archiving apps
  • SharePoint <> Slack: Syncs live Slack data into SharePoint

Despite these integrations, there is, unfortunately, no official, straightforward app that enables seamless connectivity between Slack and Teams.

iPaaS solutions: zapier, made.com, n8n, etc.

In recent years, a growing number of iPaaS (Integration Platform as a Service) solutions have emerged. These platforms allow users to connect various tools and build automated workflows.
For example:

  • When a new form is submitted on Google Forms, an email and a Slack notification can be sent to a specific channel.
  • When a new lead arrives in HubSpot, a card can be automatically added to Trello.

The possibilities are endless.

Regarding collaborative solutions, Slack and Microsoft Teams are integrated into most iPaaS solutions since they are widely used for notifications. Common actions include sending messages to specific users or channels.

However, fetching messages is often more limited, with drawbacks such as:

  • No real-time triggers (on Teams)

  • Limited message types supported

  • Additional app installations required

We tested Zapier, one of the most popular iPaaS solutions, to create a bidirectional Slack<>Teams connection. Here are our main conclusions:

  • Pros :

    • User-friendly: Easy to set up for specific use cases (e.g., syncing a few specific channels or group chats).

    • Flexible: Offers many configurable options (fields to transmit, scheduling, user inclusion/exclusion).

    • Highly connected: Can integrate with other apps (CRMs, project management tools).

    • AI assistance: Built-in AI helps with setting up workflows.

  • Cons :

    • Sync delay: New chats and messages from Teams are only fetched every 15 minutes.

    • Manual setup: New channels cannot be dynamically created and synced; each must be set up manually.

    • Limited message format: Only raw text is transmitted (no emojis, images, or files).

    • Not collaboration-friendly: Reactions and mentions are not supported.

    • Buggy: Messages sometimes get duplicated.

    • Limited visibility: No visibility on users from the other platform.

Build custom bridge

If you or members of your team have development skills, you might consider building your own Slack <> Teams integration. Both platforms offer extensive API coverage, enabling you to fetch messages, receive notifications, and send messages across platforms.
At first glance, this might seem like a relatively simple integration project. However, there are numerous hidden complexities that make it far more challenging than it appears.
Below are some key considerations:

  • Authentication & permissions
    Before starting, you must clearly define the use cases, determine which API routes to use, and establish the necessary permissions. Some permissions may require admin rights, and these vary between Slack and Teams.
    💡 Keep in mind that if you intend to connect with external users, minimizing permission requirements increases the likelihood of your integration being accepted

  • Transmission latency
    While latency is often a minor concern in asynchronous integrations, real-time messaging demands near-instant delivery. Even a slight delay of a few seconds can significantly impact user experience.

  • Security
    Slack and Teams are primarily used by professionals, making data security a critical concern. Ensuring the integrity and confidentiality of messages is non-negotiable to prevent potential data breaches.

  • User experience
    Neither Slack nor Teams natively supports cross-platform messaging, making it challenging to maintain a seamless user experience. Handling cases such as messaging users outside your organization requires careful design to avoid usability issues.

  • Asymmetrical features
    Although both platforms serve as collaboration tools, their feature sets differ significantly, leading to potential integration challenges.
    For example:

    • Slack supports threaded conversations, whereas Teams does not (in chat).
    • Teams offers message read receipts, while Slack does not.
    • Slack allows aliases, but Teams does not.
    • Teams differentiates between chats and channels, whereas Slack only has channels.

    These differences can lead to limitations or inconsistencies in the integration.

  • API changes
    Both Slack and Teams are evolving platforms that frequently introduce new features, which can impact API contracts and potentially disrupt your integration. Some changes may require substantial architectural adjustments to maintain compatibility.

Use convly 😀

And as you might expect from reading this article, we have another solution beyond those listed above: convly!
convly allows any Slack user to receive Microsoft Teams messages on Slack and vice versa. A Teams user can also get Slack messages directly in Teams.

Sounds like magic? Here’s how it works:

  • Setting up convly on Slack :

    1. Install the Slack convly app from here

    2. Connect your Microsoft Teams account

    3. Select which organizations and group chats to sync

    ✅ That’s it, you’re all set!

  • Using convly is seamless!
    Your synched Teams channels now appear in Slack allowing you to:

    • Receive and reply to all messages (with emojis 🤩)
    • Send, edit, and delete messages
    • Share pictures and documents
    • List channel members
    • Initiate DMs
    • Use mentions - @user (soon)

If you’re tired of constantly switching between Slack and Teams, convly is what you were looking for!

Get convly here