Microsoft Launches Native Slack to Teams Migration Tool for Channels

Many organizations still have years of collaboration stored in Slack, while day-to-day work now happens in Microsoft Teams. This split leaves critical conversations, threaded discussions, attachments, and team knowledge trapped in Slack, creating fragmented collaboration. It also adds pressure on organizations to manage multiple platforms and ensure that no important information is lost. This creates a clear need for a seamless migration solution.

To address this need, Microsoft introduced the new Slack to Teams migration tool in the Microsoft 365 admin center. Currently in public preview, the tool will reach general availability between late January to early March 2026. The tool is available by default, and no opt-in is required.

In this blog, we’ll explore how the tool works, what content it can migrate, and how it can simplify your organization’s transition from Slack to Teams.

The migration tool lets organizations move essential collaboration data from Slack into Microsoft Teams, such as:

• Slack Channels: Both public and private channels can be migrated.
• Channel Ownership and Membership: Owners and members of each Slack channel are mapped to the corresponding Teams channel.
• Channel Messages: Includes threaded conversations, standard reactions, and message metadata such as created by and created date.
• Message Formatting: Block quotes, bold, italics, strikethrough, bulleted and ordered lists, code, and code blocks.
• Mentions and Links: @-mentions, links, images, GIFs (GIPHY), and other media within messages.
• File Attachments: All files shared within channels are migrated.
• Canvas and List Content: Slack canvas pages are converted to HTML files, and Slack lists are converted to JSON files in Teams channels.

✅The initial release of the tool migrates only Slack channel content. Support for additional Slack content types will be added in future updates.

Note: No data is deleted from Slack during the migration process.

Before you can migrate Slack content to Microsoft Teams, a few prerequisites must be met:

Slack:

• You need permission to export your Slack workspace data. Workspace Owners, Workspace Admins, Org Owners, Org Admins, and members with the Export Admin role have the necessary access.

Microsoft Teams:

• You must have permission to import Slack data into Teams. Roles that can perform this include:
  • Microsoft 365 Migration Administrator (recommended)
  • SharePoint Administrator
  • Global Administrator
• A one-time consent must be granted by a Global Administrator to allow the migration app to import data into Microsoft 365. If not granted beforehand, the tool will prompt for consent before migration.

Azure Blob Storage:

• An Azure Blob Storage account is required to store the Slack export package.
• You must have permission to create and manage storage accounts. Suitable Azure roles include:
  • Owner (full control)
  • Contributor (create resources)
  • Storage Account Contributor (minimum requirement)
• Additionally, you need the User Access Administrator role to grant the migration app access to the Azure storage account.

The migration steps below walk through how Slack channels are moved to Microsoft Teams using Microsoft’s native tool:

1. Grant consent for the migration app: Grant one-time consent as a global admin for the Microsoft 365 Teams migration app to import Slack data into Teams. This ensures the migration tool has the necessary permissions to access Teams and perform the migration securely.
2. Export Slack workspace data: Create a Slack export package containing channels, messages, and files. This ZIP file provides the migration tool with the source content needed to transfer Slack conversations and attachments to Teams.
3. Create an Azure Blob Storage account: Set up an Azure storage account to store the Slack export package. This provides a secure cloud location that the migration tool can access for scanning and importing the data.
4. Grant access to the migration app: Assign “Storage Blob Data Reader” role for migration app to access the storage account. This allows the tool to read and scan the Slack export files without modifying the storage setup.
5. Create a Blob Storage container: Create a container within Azure Blob Storage to organize the Slack export files. This ensures that each export file has a dedicated location for easy access by the migration tool.
6. Upload the Slack export file: Upload the Slack ZIP export file into the Azure Blob Storage container. This makes the Slack content accessible to the migration tool for scanning and migration.
7. Provide the export file to the migration tool: Access the tool from the Microsoft 365 admin center -> Setup -> Migration and imports -> Slack to Teams migration. Then, link the Slack export file from Azure Blob Storage so it can access the workspace and channels for migration.

8. Scan Slack channels: Slack channels are scanned to review message counts, last activity, and content. This helps determine which channels to migrate and estimate migration duration.
9. Select channels and messages to migrate: Slack channels and messages are selected for migration, specifying all content or a specific date range. This ensures only relevant data is migrated, optimizing time and resources.

10. Map Slack users to Microsoft 365 accounts: Each Slack user is mapped to the corresponding Teams/365 account using the UI or CSV. This preserves message ownership and ensures content appears correctly under the right users in Teams.
11. Map Slack channels to Teams destinations: Each Slack channel is assigned to a destination team and channel in Teams. This ensures migrated content ends up in the correct location for continued collaboration.
12. Start migration and monitor progress: Migration tasks are launched and monitored via the migration dashboard. This ensures channels are migrated correctly, with errors or issues identified and resolved promptly.

Note: Multi-workspace shared channels are independent of individual workspaces and must be migrated separately.

After migrating Slack channels to Microsoft Teams, admins can use the Microsoft 365 Slack to Teams migration tool to generate comprehensive migration summary reports for each channel.

Using the Slack to Teams migration summary report, you can easily view key details such as:

• Names, types, and IDs of Slack channels and their corresponding Teams channels
• Total number of messages successfully migrated
• Transaction start and end times for the migration
• Channel migration status along with any error codes and messages
• Original posting timestamp of the last migrated message

These reports help administrators monitor migration progress, troubleshoot issues, and verify that critical collaboration data has been accurately moved to Teams.

While the Slack to Teams migration tool is powerful, there are some limitations and unsupported scenarios you should plan for:

• Single Slack workspace at a time: Only one workspace can be connected to the migration tool. Additional workspaces require disconnecting the current one.
• Only channel content is migrated: Direct messages, group chats, workflows, and custom app integrations are not migrated for now.
• Unsupported channel types: Slack Connect channels and archived channels cannot be migrated. Archived channels must be unarchived before export.
• Channel links and custom emojis: Links to channels (#channel_name) and custom emoji reactions are not supported.
• File attachment restrictions: Filenames with characters restricted by SharePoint are automatically replaced with underscores (“_”) during migration.
• Slack canvas and list files: Canvas pages migrate as HTML attachments, and Slack lists migrate as JSON attachments.
• Message count differences: Total migrated messages may differ from Slack’s total messages, e.g., thread replies may appear as separate messages in Teams.
• Attachment metadata not migrated: Metadata like Created at, Created by, Last edited at, and Last edited by is not preserved in Teams.

We hope this blog has given you a clear overview of the new Slack to Teams Migration Tool. Thanks for reading! For further queries, feel free to reach out to us through the comments section.