Rated 5 out of 5 stars

lightweight addon @8kb , also useful for copying links in google search results

This review is for a previous version of the add-on (1.3.2). 

File sizes aren't really meaningful - e.g. here 5 kB are taken up by the extension signature which has no impact on anything. But yes, it is built as a very lightweight extension. E.g. it takes up 80 kB of memory for me which should be as low as it goes.