Reload extension

There are two main way to reload an extension.

use Extensions Reloader

If you like you can custom shortcuts, you can find keyboard shortcuts in the bottom of chrome://extensions page.

develop directly in that page

You can open a extension page by chrome-extension://{extension-id}/{page.html}

Debug

If you do not right test, you have to use console.log to do debugging.

I we use console.log in background page, you can see nothing in the page console...

But you can see these by using chrome message passing.

You can find more detail in this article