grunt : Grunt is a task-based command line build tool for JavaScript projects
📦 Parcel : Blazing fast, zero configuration web application bundler
Online javascript beautifier : Beautify, unpack or deobfuscate JavaScript and HTML, make JSON/JSONP readable, etc.
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.
Adds static typing to JavaScript to improve developer productivity and code quality.