There is a firefox add-on called: search this site: https://addons.mozilla.org/af/firefox/addon/92023/

I don't know if it's any good cause I never used it. I'm using similar extension on chrome ( https://chrome.google.com/extensions/detail/ampaaokifoiijaegiboaoncicpekfbdo ) thought and it works flawlessly.

And you can always use google site feature just like John T suggested.

There is a firefox add-on called search this site

I don't know if it's any good cause I never used it. I'm using a similar extension on chrome thought and it works flawlessly.

And you can always use google site feature just like John T suggested.