TABLE OF CONTENTS



Run the Slack Calls Diagnostic Test

  • From a channel or direct message (DM), type the /call --test slash command in the message field, then send the message.
  • The test will run automatically in a new window. Scroll to the bottom of the page to view any errors.
    • Note: If you see an error message when running the test from the desktop app, try it from Slack in your Chrome browser instead.



Troubleshoot Bandwidth Issues

  • Bandwidth Requirements: If you experience issues with call quality, see “Bandwidth quality” to learn about network connection strength.
  • Troubleshoot: If your bandwidth meets or exceeds the requirements and you experience issues, try one of these options: 
    • Run a speed test to double-check that your device's bandwidth meets the audio and video call requirements. 
    • Switch to a wired connection if possible, or move closer to your Wi-Fi router. 
    • Reset your router by turning it off and back on again. 



Resolve Call Connection Problems

  • If you are not on the latest version, update your Slack app. 
  • If you have trouble with calls on the desktop app, open your workspace in Google Chrome and try making a call. 
  • If calls do not connect from the desktop app or browser, try starting a call from the Slack mobile app on the same Wi-Fi network. 
    • If the call connects, there may be an issue with your computer, like an anti-virus software blocking the connection. 
    • If you can make calls from your mobile device with data but not Wi-Fi, that most likely indicates an issue with your network. 
  • Update firewall settings if you receive errors when running tests.



Resolve Audio Issues

  • If you experience audio issues during a call, quit and reopen the Slack desktop app or your browser. You can also restart your device.
  • Check Audio Input and Output Sources
    • Click the “Phone” icon to start a call. 
    • Click the “Gear” icon in the top left corner of the call window. 
    • Select your input or output source to open a drop-down menu and select your preferred microphone and speaker. You can switch between sources to see which ones work. 
    • Test your microphone by saying a few words and check that the voice meter moves up and down as you speak. 
    • Click “Test” to check your speaker. You will hear a chime if your speaker is unmuted and working correctly.  
  • You can also Check Audio Settings on a desktop, iOS, or Android to make sure system preferences and settings allow access.



Resolve Video Issues

  • If you experience audio issues during a call, quit and reopen the Slack desktop app or your browser. You can also restart your device.
  • Check Camera and Video Settings
    • If you are using the Slack desktop app, check if video calls work from Google Chrome. If you are using Chrome, check if video calls work using the Slack desktop app.
    • Click the “Gear” icon in a call window to check your video settings and make sure the correct camera is selected. You should see yourself in your own video thumbnail.  
    • Check if your camera works with another calling app to see if there is a hardware issue with your camera. 
  • You can also Check Camera Permissions on a desktop, iOS, or Android to make sure system preferences and settings allow access.



Resolve Screen Sharing Issues

  • Windows
    • If you are using Windows 10 on a laptop that is closed, open the laptop. 
    • Unplug or undock any external monitors. 
  • Mac : If you are running macOS version 10.15 and cannot share your screen, check your operating system settings:
    • Open System Preferences. 
    • Click “Security & Privacy,” and then select the “Privacy” tab. 
    • Select “Screen Recording” from the list on the left. 
    • Click the “Lock” icon to make changes. 
    • Check the box next to Slack, and then click the “Lock” icon again to save your changes. 
    • Quit and reopen the Slack desktop app. 



Additional Support



Adapted from Slack