The Style.Tools project started as a free browser-widget that provides a sort of DevTools (developer tools) for frontend optimization (FEO).
Style.Tools is available with 1 click on any page on the internet, including pages behind a login.
Start Style.Tools🔬 FEO (drag the link to the favorites bar to install the widget)
Style.Tools provides access to advanced CSS optimization tools including:
The widget provides localhost and offline support via a Service Worker on domain style.tools. You can use many of the features locally without an internet connection. The cache for preferences is preserved across domains.
The widget is a small piece of Javascript code that can be added to the browser bookmarks or favorites bar via the URL prefix javascript: