Firefox Developer Edition

Firefox Developer Edition brings you latest features, fast performance, and the development tools you need to build for the open web. Its powerful development tools will extend your ability to work across multiple platforms from one place.

Firefox DevTools features:

Master CSS Grid
Page Inspector
Web Console
JavaScript Debugger
Network Monitor
Storage Panel
Responsive Design View
Visual Editing
Shapes Editor
Web Audio Editor
CSS stylesheets Editor
Scratchpad
Performance Tools
Memory Tools