Selectify

If you are writing jQuery, you frequently decide and write the optimum jquery selector for your need. However, the rules for optimizing a jQuery selector are relatively easy and can be automated. That's what this extension is for. Instead of having to step through the DOM, find the ID which could be anywhere, and try to remember again exactly what the rules are for optimizing the jQuery selector, this tool builds the selector and copies it to your clipboard. Done! Voila! Additionally, the tool tells you how many elements on the page that selector calls so you instantly know whether the selector is unique (calls only one element) or not (calls many elements).

The readme.md file delineates the logic used. Primary source behind the logic is: https://learn.jquery.com/performance/optimize-selectors/