Prettier : Prettier is an opinionated code formatter. It enforces a consistent style by parsing your code and re-printing it with its own rules that take the max...
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 ...
ESBench : Shareable JavaScript Benchmarking
Built-in ES2015 support, powered by Babel
Statistically significant benchmarks, powered by Benchmark.js
nwb : A toolkit for React, Preact & Inferno apps, React libraries and other npm modules for the web, with no configuration (until you need it)
Beautify, unpack or deobfuscate JavaScript and HTML, make JSON/JSONP readable, etc.