Developer tools not working on managed guest sessions

Problem

How can you enable Chrome Developer tools on managed guest sessions?

Environment

  • ChromeOS
  • Chromebooks

Solution

To resolve this issue you must change the URL blocking pattern. To do so follow the steps described below:
  1. In the Admin console.
  2. Go to Devices > Chrome > Settings > Managed guest session.
  3. Look for the URL blocking.
  4. Under Blocked URLs use the https:// and http:// patterns.
  5. Look for the developer tools.
  6. Change the setting 
Workaround:
If it's a kiosk app check the KioskTroubleshootingToolsEnabled policy in the device settings.

Cause

Blocking all URLs or chrome:// and chrome-untrusted://  URLs can lead to unexpected errors or can be circumvented in some cases. Instead of blocking certain internal URLs, see if there are more specific policies available.