Search on WaniKani от Royalnb, Joe Anderson

Select any text on the web page and right-click to open the context menu where you can select "Search on WaniKani". You can then choose "Search Kanji on WaniKani" or "Search Vocabulary on WaniKani". This will take you straight to WaniKani.com and look up the highlighted kanji or vocabulary.

Modified from Ollie's Search-on-Kitsun.io