Eruda

With Eruda you can display JavaScript logs, check dom state, show requests status, show localStorage, cookie information, show url, user agent info, include snippets used most often, Html, js, css source viewer, and install. The JavaScript file size is quite huge(about 100kb gzipped) and therefore not suitable to include in mobile pages. It's recommended to make sure eruda is loaded only when eruda is set to true. When initialization, a configuration object can be passed in. Container element, if not set, it will append an element directly under html root element. Choose which default tools you want, by default all will be added. There are several available plugins, like eruda-fps, which displays page fps info, eruda-features, which will let you see feature detections, eruda-timing, to show performance and resource timing, eruda-memory, to display page memory info, eruda-code, to run JavaScript code, and many more.