Firefox Tools - Mozilla Firefox Browser | Browsers
Standards Based Development
Web Development Tools Integrated into Firefox
Page Inspector
Displays the html of the element currently being pointed at with a mouse, in context. Chrome's is inspect element.
Web Console
The web console allows you to interactively output information, run JavaScript snippets, and experiment with content.
Scratchpad
A text editor built into Firefox allowing for editing and running JavaScript code.
Style Editor
Permits editing of css styles on the current document in real time; additionally, they can be toggled on and off, providing in-browser development in real time.
JavaScript Debugger
Permits stepping through JavaScript code running in the browser (or even on a remote browser!) and watching variables to help track down bugs. This documentation also covers the Remote Debugger, which can be used to debug code running on a Firefox os device or in Firefox running on an Android device.
Responsive Design View
Lets developers view designs in different screen sizes without changing the overall size of the browser window.
Using the Source Editor
Source Editor isn't a standalone tool; instead, it is the underlying editor used by Scratchpad and the Style Editor.
Developer Toolbar
Developer Toolbar provides a command-line interface for manipulating and working with Firefox's developer tools, and buttons for quick access to the most commonly used tools in web development.