Private Channels in Slack and Teams: Create, Convert and Share
Both products have private channels, but they disagree on a fundamental question: can you change your mind? Slack says yes, with caveats about files and Slack Connect. Teams says never; a channel keeps the type it was born with. Here is what each help page documents.
Miles Crawford
The quick version
In Slack, open the channel, click the channel name in the conversation header, go to the Settings tab, and choose Change to a private channel (or back to public). In Teams, there is no conversion at all: standard, private and shared channels each keep their type permanently, so the choice happens when the channel is created. Teams private channels are invite-only spaces inside a team, and only team owners can create shared channels.
Slack: converting a channel
Slack channels are public or private from creation, and the setting can change later. From the desktop app, open the channel, click its name in the conversation header, select the Settings tab, scroll down and click Change to a private channel, then confirm. Converting back to public follows the same path. By default, owners, admins and Channel Managers can convert a channel to private, while converting to public takes a Workspace Owner, Org Owner or Org Admin; owners can restrict either. A message posts in the channel to tell members it was converted, and on Business+ and Enterprise plans, owners and admins can also convert channels to private with channel management tools.
Slack: the caveats that matter
Three limits are worth knowing before you convert. Files shared in a channel that goes public become public too, and they stay public even if the channel is converted back to private. Slack Connect channels that are private in the owning organization cannot be converted to public, and any conversion of a Slack Connect channel applies only to the organization that made the change. And the #general or #all-company channel can never be converted to private.
Teams: three channel types, chosen once
Microsoft describes three types. Standard channels are open to all team members, and anything posted is searchable by others. Private channels are for discussions that should not be open to the whole team: you must be invited to join one, any team owner or member can create one by default (guests cannot), and the channel is permanently linked to its parent team. Shared channels are for collaborating with people inside and outside your team or organization; only team owners can create them, only shared channel owners can add members, and admins must enable B2B direct connect before people outside your org can join. Critically, Microsoft states you cannot convert between types in either direction: standard, private and shared are all permanent choices.
Teams: files and meetings in private channels
Files shared in a private channel live in a separate SharePoint site from the rest of the team's files and are viewable only by channel members; a team site in SharePoint is created automatically for a new team or private or shared channel. For meetings, external guests can join a private channel meeting or Meet now call only if a channel member sends them the join link or calls them in, and their access to chat, files, whiteboard, notes and the participants list lasts only for the meeting.
Which one for what?
Our read: Slack's convertibility is forgiving when a channel's purpose drifts, but treat the file rule as one-way; once files go public they do not come back. In Teams, decide the audience before anyone posts, because there is no fix short of a new channel. If the audience includes people outside the team, the Slack path is Slack Connect and the Teams path is a shared channel; both are covered in our Slack Connect vs shared channels guide.
What to be careful about
- Public is sticky for files in Slack. Files exposed by a conversion to public stay public even after converting back.
- Teams channel type is forever. There is no conversion between standard, private and shared, per Microsoft.
- #general stays public. Slack's #general or #all-company channel cannot go private.
- Guests cannot create private channels in Teams. Team owners or members can, unless an admin restricts it.
- Slack Connect conversions are per-org. Converting a shared Slack channel only changes it for your organization.
Sources
Checked October 24, 2026. Conversion paths, permissions and limits follow each product's own help articles. The guidance on when to use each is ours.