Domain Link Highlighter

Highlight links: green (dofollow), neon yellow (nofollow), orange (sponsored). Toggle per-site or All Links from the toolbar.

Highlights links found that go to a list of domains you specify, and highlights nofollow/sponsored links a separate color. You can include or exclude what sites the tool works on, and there is a "highlight all links" mode. This tool is primarily useful to SEOs and is particularly nice for being able to easily find links in the SERPs to the sites you are working on, but also has application for PR and affiliate marketers to easily identify where your links appear on a web page. This tool does not collect or send any information. Based on an extension originally created by Cari Davidson at Wayfair, which was removed after not being updated in over a decade (but I used every day up to the day it was taken down).