Microsoft Teams does not import Slack history natively. You export what your Slack plan allows, move files into Teams channel libraries, and either use a third-party tool to recreate channel history or keep the Slack export as a separate archive. Direct messages cannot be imported into Teams at all, according to Microsoft’s own guide. And what you can export depends on your Slack plan: every plan gets public channels; private channels and DMs need Business+ or Enterprise and a request to Slack.

What Slack lets you export

Slack plan Public channels Private channels and DMs
Free Yes (messages and file links) No
Pro Yes No
Business+ Yes Owners can apply for a self-serve export tool; the Primary Owner must approve
Enterprise Yes Org owners ask Slack support to enable export tools (custom, all conversations, or channel audit)

Exports are JSON files with messages and links to files. Download the files you need separately; links can stop working when the workspace closes.

What Teams can take

Microsoft’s guide sets out the limits:

  • Channel messages: no native import. Free tools on GitHub (Microsoft names ArgyleMigrator and Slack Export Viewer) and paid migration services can recreate or display history.
  • Direct messages: not supported for import. Keep them in the export.
  • Files: copy exported files into the matching document libraries of your Teams channels.

A sensible plan

  1. Keep your Slack plan until the export is done. Downgrading a workspace to free starts the one-year deletion rule, and Slack says deleted history can’t be restored.
  2. Request the fullest export your plan allows, early: Business+ and Enterprise exports need approval.
  3. Decide what moves into Teams: usually active channels and recent files.
  4. Archive the rest in a searchable form, owned by someone on the team.
  5. Close the Slack workspace only once the archive is checked.

Years of chat history are records

Slack history shows how a team actually worked: decisions, handoffs, customer issues, fixes. It is also the kind of record some AI developers license, in de-identified form, from established US companies; Mercor and Troveo both list Slack among the tools they take data from. If the history is worth keeping, decide what to do with it before the workspace is closed.

Questions people ask

Can Teams import Slack direct messages?

Microsoft's migration guide says Teams doesn't currently support importing direct messages. It points to partner tools and to Slack's own export options.

What if we downgrade Slack to free before migrating?

Don't. On free workspaces Slack deletes messages and files older than one year on a rolling basis, and deleted history can't be restored.

Sources

  1. Microsoft Learn: Migrate from Slack to Microsoft Teams
  2. Slack Help Center: Export your workspace data
  3. Slack Help Center: Updates to message and file history on free workspaces

What to do with old email archives when you move to Microsoft 365 or Google Workspace

Migrate, archive or let go: how to handle years of old email when switching between Google Workspace and Microsoft 365, and when the old vendor deletes it.

What to do with company email, Slack and files when you close

How Google Workspace, Microsoft 365 and Slack delete data after you cancel, how to export first, what to keep, and what the archive may be worth.

How to export Slack data, plan by plan

What Slack exports on Free, Pro, Business+ and Enterprise, the free plan's 90-day and one-year limits, and why deleting a workspace is permanent.

Part of Migrating systems.