Issues connecting to Slack

Having trouble connecting to Slack? We’ve gathered some of the common issues people face and the steps you can take to fix them before reaching out for support.

What causes connectivity issues?

  • Outdated web browsers, plugins, or extensions
  • Slack detects conflicting software or security settings
  • Outages or disruptions with third-party services
  • Slack app storage or errors with Slack servers

Check Slack status: Pop over to to see if we have any known issues or bugs that we're working hard to resolve.


Check your Slack app

To start, make sure you are using the most up-to-date version of Slack:

  1. Click Slack in the menu bar of your computer.
  2. Click Check for Updates

If Slack seems slow or struggling to connect, it may help to clear your cache or local storage. If that doesn't help, reducing the amount of data your workspace is processing may do the trick. Here's how:

🚮   Clear cache or local storage




Windows Phone

  1. Click Help in the menu bar of your computer.
  2. Select Troubleshooting and click Clear Cache and Restart.
  1. Swipe left to open your profile sidebar.
  2. Tap Settings.
  3. Choose Advanced.
  4. Select Reset Cache.
  1. Tap the   three dots at top right.
  2. Choose Settings.
  3. Select Advanced.
  4. Tap Reset local storage.

Restart the Windows Phone app:

  1. Tap the back button in Slack to close the app.
  2. Force quit by long-pressing the back button, then tapping the   close icon by the Slack preview. 

 📖   Manage your unread channels

Mark channels as read by pressing the Esc key while viewing the channel. Or, hit Shift + Esc to mark everything as read.

🖼   Close images and files

Do you have lots of expanded images, animated GIFs, and files in your channels? You can close or hide images in Slack. Here's how:

  1. From your desktop, click your workspace name in the top left.
  2. Choose Preferences from the menu.
  3. Select Messages & Media, then uncheck the boxes next to Show images and files from linked websites and Show images and files uploaded to Slack.


Test your web browser and internet connection

📶   Try Slack in a browser

If you’re using a desktop app, test your connection by opening your workspace in a browser. If you’re unable to connect, check your browser settings:

  • Make sure your browser is up to date and supported by Slack: Slack supports the current versions of Chrome, Firefox, Safari, Internet Explorer, and Edge. You can check if you’re running the most recent version of your browser by visiting Read more about our support for web browsers
  • Try connecting to Slack in a different browser: If you can't connect from a supported browser, there may be a problem specific to that browser. Try Slack in another supported browser.
  • Turn off browser plugins or extensions: Disable them one at a time to find out if any could be causing an issue.


📶   Test your connection

On desktop or mobile, visit to check your connection to Slack.

Successful tests will display in green, failures or errors in yellow. 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 with Fastly, Slack's content delivery network (CDN). Please contact our support team.
  • Server connection error: If does not load, check that your network is set to allow outbound TCP connections to port 443. If loads but you still see an error, contact our support team.


Look for conflicting software, security settings, and firewalls

Certain software can sometimes interfere with Slack connections:

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

🔎  Scan your computer for spyware or adware.

Malicious software can intercept outgoing traffic and cause issues with connecting to Slack.


🚨  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 allow *


🚨  Adjust your proxy or firewall settings

Note: Our servers are reassigned dynamically within our hosting environment, so we don't have a list of static IP addresses to share.

Proxies and firewalls can sometimes interfere with your connection to Slack. If you need help configuring your firewall or proxy, contact your network administrator or an IT professional.

Slack uses WebSockets, a persistent connection between your browser or app and our messaging server, over port 443. Your firewall and/or proxies must be configured to keep these connections open. If you’re struggling to connect, here are a few steps that can resolve the problem:

  1. Whitelist (allow) the following sites: * * * * * * *
  2. Check if your proxy is running SSL decryption. If it is, the proxy must either support WebSockets, or you’ll need to exempt * from SSL decryption.
  3. If you’re running Slack on a Mac, head to your computer’s System Preferences, then Network, Advanced, and under Proxies, check that Auto Proxy Discovery is disabled.

If you did not configure your network security, this might sound a bit confusing: please contact your trusted IT professional for additional assistance.


🚨  Troubleshoot for call connectivity in Slack

Speaking of firewalls, they’re often the reason for most call connection issues. If Slack is having trouble establishing a connection or connecting to the server, read up on troubleshooting for connection errors while making calls in Slack.

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


Contact Slack support

If you've followed the steps above and are still unable to connect to Slack, please reach out to our helpful support team, available 24/7.

You can start by sending us a message mentioning issues with connection/connectivity in the subject line. Please remember to:

  • Copy and paste your results from
  • Describe the action you’re trying to perform, and what’s going wrong.
  • Tell us about the troubleshooting steps you’ve tried.
  • Add screenshots of error messages or other helpful displays.

We'll do everything we can to help!

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