Troubleshoot Slack connection issues

Having trouble connecting to Slack? Here’s what you can do:

Switch to a browser

If you’re using a Slack desktop app for Mac or Windows, test your connection to Slack in a browser. If you’re still unable to connect, continue with the troubleshooting steps below.

Check your browser settings

  1. Make sure your browser is up to date.
    Slack works well in the current versions of major browsers, such as Firefox or Chrome.
  2. Try connecting to Slack in a different browser.
    If the problem is browser-specific, you’ll be able to use Slack in another browser.
  3. Open Slack in a private browser window.
    If you’re only able to connect to Slack in a private window, check your computer for conflicting software (more on this below).
  4. Turn off browser plugins or extensions.
    One of these could be causing an issue with Slack.

Note: To use Slack Calls on the web, you'll want to make sure you're using a Chrome browser.

Look for conflicting software

  1. Scan your computer for spyware or adware.
    Malicious software can intercept outgoing traffic and cause issues with connecting to Slack.
  2. Temporarily turn off any antivirus or ad-blocking software.
    This may include applications such as McAfee, Norton, or AdBlock Plus. If you’re then able to connect to Slack, one of these applications is causing an issue. Update the software settings to exclude or whitelist *

Software that can sometimes interfere with Slack connections:

  • Avast
  • AVG
  • Avira Browser Safety
  • Browser Guard
  • Pokki
  • Smart Panel
  • Spyware and adware
  • Visual Discovery by Superfish

Test your connection

Visit to run a simple test that will check your connection with Slack.

Successful tests will display in green, failures or errors in red. Here's what the results may indicate:

  • Failing WebSockets
    Software or firewall settings may be interfering with your connection to Slack. See details in the next section.
  • Low bandwidth
    If your bandwidth results are in kbps (rather than mbps), the problem is due to a slow internet connection.
  • Failing jQuery or CDN
    There may be a problem connecting to Fastly, Slack's content delivery network (CDN). Please file a support request.
  • Server connection error
    If does not load, please check that your network is set to allow outbound TCP connections to port 443. If loads but you still see an error, please file a support request.


Adjust your proxy or firewall settings

Proxies and firewalls can sometimes interfere with Slack connections. Whitelisting the following sites often resolves the problem: * * * * * * * 

If you need help configuring your firewall, consider contacting your network administrator or an IT professional.

Contact Slack Support

If you've followed the steps above and are still unable to connect to Slack, please send us the following details in a support request:

  • Copy and paste your results from
  • Tell us about the troubleshooting steps you’ve tried.

With that information, we’ll do all we can to help! 

Related Articles

Recently Viewed Articles