I thought it was quite compact already, what do you think should be the message?

1) "The link was copied to clipboard"
2) "https://goo.gl/____ was copied"
3) "Success!"
4) Something else?

ps. You can edit your comment and add a reply to this question.

pps. I think the notification is quite important because it is only triggered when the link is copied, which becomes relevant in slower or problematic connections.

Firefox API does not allow to control any of these options, they are either firefox global options (which I could not find), or system-wide options for notifications.

Another user suggested disabling the notifications, would that work for you? (personally I don't like it that much because in bad connections the link creation is not immediate)

edit: link to API description https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/notifications/NotificationOptions

In theory it should be compatible with firefox mobile, but I tested and it does nothing. Maybe the API is not fully implemented in mobile.

I would like to implement the bit.ly backend option, but using a default key would severely limit the number of links that can be shorten.

ps. thanks for the feedback!

I'll look into integrating bit.ly, my attempts so far were failed because I could not find a way to have a generic key that supported more than 10.000 calls a day (which is very restrictive)... I must be missing something as previous extensions such as shortly was using bitly.

thanks for the feebback!