My Google Chrome developer tools are disabled. I'm not sure how it happened. I was using them in the morning then went to use them in the afternoon and the F12 button wouldn't do anything. Same with ctrl+shift+i.
If I navigate the 'Tools' menu, I can see the 'developer tools' link, but it is grayed out and disabled. Does anyone have any idea how to re-enable them? I uninstalled/re-installed chrome twice but no help.
Delete the DeveloperToolsDisabled registry key in Software\Policies\Chromium\DeveloperToolsDisabled
http://www.chromium.org/administrators/policy-list-3#DeveloperToolsDisabled
I found it named slightly differently (Win7):
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\DeveloperToolsDisabled
I set it to zero and restarted Chrome --> all is well. No idea how it got set.
Update 5/30/2014: This value was set again, there must be some security policy against this flag where I work. I deleted the key completely and will report back if it appears again.
Update 6/13/2014: Definitely we've got a security policy that is setting this key daily. As a workaround I've created a file, "fix_developer_options.reg" with the following contents and put it on my Desktop:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome]
"DeveloperToolsDisabled"=dword:00000000
This file, when double-clicked, will automatically make this setting in the registry. After that, you need to restart Chrome to get the change. (One step better would be to have this executed when you log in.)
Update 3/4/2018: In Windows 10 this setting has moved under HKEY_CURRENT_USER as @DGinzberg mentions below in the comments. I found it here on a new computer:
[HKEY_CURRENT_USER\SOFTWARE\Policies\Google\Chrome]
check policies - type chrome://policy/ in url bar. if DeveloperToolsDisabled is set to true, update the registry entry
Found another issue with the Dev Tools not opening/ working
If the Block access to a list of URLs Enabled and "file", "" is in it or file:// is not in the whitlist of url, the DEV Tools wont open either :)
Maybe that helps someone
Open regedit (Registry Editor) and find the DeveloperToolsAvailability key by first going to this path:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\
... then click Chrome and select DeveloperToolsAvailability from the list on the right. Double click it and change it from 2 to either 1 or 0. Click OK and close regedit, then close Chrome and re-open it. Chrome dev tools should now be enabled.
However, depending on your system, you may instead have the DeveloperToolsDisabled key in that same path. If so, delete that.
来源：https://stackoverflow.com/questions/19726308/google-chrome-developer-tools-disabled