Here's the introduction: https://support.mozilla.org/en-US/kb/bookmarklets-perform-common-web-page-tasks https://support.mozilla.org/en-US/kb/bookmarklets-perf

Here's the introduction: https://support.mozilla.org/en-US/kb/bookmarklets-perform-common-web-page-tasks https://support.mozilla.org/en-US/kb/bookmarklets-perform-co... When you properly install it, instead of the link, there should be an executable code in the bookmark (if it starts with http: or something, it isn't). To activate the code, first you visit the page on which you want the code to work, then you click at the bookmarklet.