How to Make a Slack Channel Private (and the Files Catch)

Sometimes a channel starts life public and then the conversation turns sensitive: a client's numbers, a hiring decision, a project that isn't announced yet. Slack lets you convert a public channel to private in a few clicks. There are a couple of rules around files and the general channel worth knowing before you do. Here's the process and what changes.

Convert a channel to private

1. On your desktop, open the channel.
2. Click the channel name in the conversation header.
3. Select the Settings tab.
4. Scroll down and click Change to a private channel.
5. Click Change to Private to confirm.

Slack posts a message in the channel telling members it's been converted, so nobody is surprised. These steps are for the desktop app.

Who can do it

Change	Who can, by default
Public to private	Workspace Owners and Admins, Org Owners and Admins, and Channel Managers
Private to public	Workspace Owners, Org Owners and Org Admins

Owners can restrict either permission, so if you can't see the option, find an owner and ask. On Business+ and Enterprise plans, owners and admins can also convert channels using Slack's channel management tools.

Can you change it back?

Yes, though fewer people can. Older guides online say converting to private is permanent, but Slack's current help article includes steps to convert a private channel back to public: channel name, Settings, Change to a public channel, then Change to Public. By default only owners and org admins can do that, so check with them first.

The files catch

This is the one to read twice. Slack says that if a channel is converted to public, the files shared in it become public too, and they stay public even if the channel is later switched back to private. So be careful with the reverse direction: making a private channel public exposes its files for good, and flipping it back afterwards doesn't undo that.

Channels you can't make private

• The #general or #all-company channel can't be converted to private.
• Slack Connect channels shared with another organisation follow their own rules: a channel that's private in the organisation that owns it can't be made public, and other conversions only apply to the organisation that made them.

Better still: make it private from the start

Slack lets you choose public or private when you create a channel, so if you already know a channel will hold sensitive material, set it as private at creation rather than converting later. That avoids the awkward window where a channel is briefly public, files and all, before someone notices. It's a good habit for client channels in particular: create them private, add only the people working on that account, and there's nothing to fix afterwards.

Private or public: which should it be?

Slack's own description is a good test: public channels are for information anyone can find and read, private channels for discussions that shouldn't be open to everyone. In practice, I'd keep most work public, because it's searchable and saves people asking the same questions. Go private for client-specific work, HR, finance, leadership discussions and anything under NDA.

What changes for members

Slack's message in the channel tells existing members about the change. What changes is who the channel is for: a private channel is meant for its members only, so anyone new needs to be added by someone already inside. Converting is about future access, so if someone already in the channel shouldn't be there, remove them as a separate step rather than assuming the switch does it for you.

A safer alternative for sensitive topics

If only part of a conversation is sensitive, it's often cleaner to start a separate private channel for it and leave the original public. That way the general project discussion stays open and searchable, and the sensitive part lives where only the right people can see it. Name it clearly so its purpose is obvious, for example with a prefix from your workspace's naming guidelines, which Slack recommends to keep channels consistent.

Before you convert, a quick checklist

• Check who's in the channel and whether everyone should be.
• Check what files have been shared, especially if you might ever make it public.
• Tell members why it's going private, so the system message doesn't cause alarm.
• Update the channel description to say it's private and who it's for.
• Pick a quiet moment, so the conversion message doesn't land in the middle of a busy discussion.

If the channel's work is finished rather than sensitive, archiving is usually better than making it private, and if you're the one who no longer needs it, simply leave the channel.

My verdict

Convert from the channel name, Settings, Change to a private channel, if you're an owner, admin or Channel Manager. Remember #general can't go private, and think hard before ever going the other way, because files in a channel made public stay public.

Frequently asked questions

How do I make a Slack channel private?

On desktop, click the channel name, open the Settings tab, click Change to a private channel and confirm with Change to Private.

Who can make a Slack channel private?

By default, Workspace Owners and Admins, Org Owners and Admins, and Channel Managers. Owners can restrict this.

Can a private Slack channel be made public again?

Yes. Slack's help includes steps to convert to public, which Workspace Owners, Org Owners and Org Admins can do by default.

Can I make the general channel private in Slack?

No. Slack says the #general or #all-company channel can't be converted to private.

Do Slack members know when a channel goes private?

Yes. Slack posts a message in the channel to let members know it's been converted.