Prepack : Prepack is a tool that optimizes JavaScript source code: Computations that can be done at compile-time instead of run-time get eliminated. Prepack rep...
DOM Monster Bookmarklet : DOM Monster is a cross-platform, cross-browser bookmarklet that will analyze the DOM & other features of the page you're on, and give you its bill of ...
JSHint : A JavaScript Code Quality Tool. JSHint is a tool that helps to detect errors and potential problems in your JavaScript code.
The pluggable linting utility for JavaScript and JSX