Firefox Developer Edition

November 3, 2015

Version 44.0a2, first offered to Firefox Developer Edition channel users on November 3, 2015


  • Improved warning pages for certificate errors and untrusted connections


  • Firefox has removed support for the RC4 cipher


  • Developer Information
  • Right click on a logged object in the console to store it as a global variable on the page

  • Visual tools for Animation:

    • View/Edit CSS animation keyframe rules directly in the inspector
    • Visually modify the cubic-bezier curve that drives the way animations progress through time
    • Discover and scrub through all CSS animations and transitions playing on the page
    • Learn more: http://devtoolschallenger.com/
  • Visual tools for Layout and Styles:

    • Display rulers along the viewport to verify size and position and use the measurement tool to easily detect spacing and alignment problems
    • Use CSS filters to preview and create real-time effects like drop-shadows, sepia, etc
    • Learn more: http://devtoolschallenger.com/
  • New memory tool for inspecting the memory heap

  • Service Workers API

  • Built-in JSON reader to intuitively view, search, copy and save data without extensions

  • Add-on signing enforcement

All Firefox Developer Edition downloads