How-To

How to Make Calls and Send Private Messages in Slack

By Bryan M. Wolfe

Updated November 27, 2023

Slack’s integrated calling feature works well on both the desktop and mobile. Best of all, it works with no additional setup.

Slack is one of the most popular team communication tools in the world. Though primarily known for its in-app private and direct text messaging, Slack also lets you make calls. Here’s how to make your Slack messages private and make calls to your Slack contacts.

Different Plans

Some, but not all, of the features mentioned below, require a paid Slack account. Currently, the following account types are available through the service:

• A free version of Slack (the default) offers 10k searchable messages, 10 apps and integrations, one-to-one video calls, and two-factor authentication.
• For as little as $6.67 per person, per month, you can get a standard plan. Features include unlimited message archives, unlimited apps, group calls with screen sharing, guest accounts, and shared channels.
• Plus and enterprise accounts are for large businesses. These start at $12.50 per person per month.

Sending Private Messages in Slack

Public channels in Slack are just that, public. By definition, this means anyone team member in a workspace can join the channel and communicate with other members. Private channels, by contrast, are ideally suited for private conversations among smaller sub-groups. These private channels can be used to organize large teams.

Only Workspace Owners and Workspace Admins, and Org Owners and Org Admins can convert a channel to private in Slack. Once you make a channel private, it can never be made public again. You can only turn a public channel into a private one through the web; the option is not available through the Slack app for iOS or Android.

To convert a public channel to one that is private through the web:

1. From your desktop, open the channel you’d like to make private.
2. Click on the details icon at the top right.
3. Choose More …, then Additional options.
4. Choose Change to a private channel.
5. Click Change to Private to confirm.

Convert Direct Messages Into a Private Channel

Group direct messages, or DMs, in Slack are conversations between three or more people. When these become long-term discussions, or you want to add more than nine people, you can convert the DMs into a private channel.

1. 1. From your desktop, open the Slack DM you wish to convert.
   2. Click Details at the top right.
   3. From the menu, select Convert to a private channel.
   4. To confirm, click Yes, continue.
   5. Enter a name for the new channel.
   6. Click Convert to a private channel.

Note: Only members with permission to create private channels can move a group DM to a private channel.

Making a Call in Slack

With Slack calls, you can make a voice or video call and connect with any member of your workspace.

Voice calls are available through your desktop and mobile devices, while video calls are only available through the desktop at this time.

To call another person with Slack calls, they must be part of the same workspace. Individuals can make voice calls through DMs on both free and premium Slack plans. However, to start a call from a group DM or a channel, you must have a paid subscription.

Calls with more than two people can have a total of 15 participants.

To make a voice call through a direct message on the desktop:

1. Open a direct message.
2. Click on the Phone icon at the top right.
3. Begin your call (yes, it’s that easy!)

For those with a Slack Standard, Plus, or Enterprise Grid plan, you’ll also notice a camera icon, which allows you to switch to a video call automatically.

To make a voice call through a channel on the desktop:

1. Open the channel.
2. Click on the Detail icon at the top right.
3. Choose Call.

Slack posts a message to the channel and any member (up to 15) can join the call by clicking on the Join button.

Again, for those with a Slack Standard, Plus, or Enterprise Grid plan, you’ll also notice a camera icon, which allows you to switch to a video call automatically.

To make a voice call through the Slack iOS or Android app:

1. Open a channel or direct message.
2. Tap the channel or DM name at the top of the screen.
3. Choose to Start a Call.

Inviting Others to a Call

1. Choose the invite icon at the top left corner of the call window.
2. Type of the person’s name in the box.
3. Select the member.
4. Click Invite.