Getting error while detect chrome extension installed or not using javascript

Question

Here is My code,

var myExtension = chrome.management.get( \"my_extention_id\" );
if (myExtension.enabled)
{
// installed
}
else { ... }

sou

Answer 1

If it's undefined then you're missing the management declaration in the manifest:

"permissions": [
          "management"
        ],

Source

Answer 2

Check in another extension:

https://gist.github.com/greatghoul/321b4f32c0b7a6ad8a97

Check in webpage

https://developer.chrome.com/extensions/messaging#external-webpage

In manifest file, remember to register webpage you want to check extension from.

"externally_connectable": {
    "matches": ["*://developer.chrome.com/*"]
}

then you can use chrome.runtime.sendMessage in that page.