Mozilla recently released a new Developer Edition for web developers to use, but how much difference is there between it and the regular version of Firefox? Today’s SuperUser Q&A post has the answers to a curious reader’s question.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

The Question

SuperUser reader Saurabh Lprocks wants to know what is different between the regular and developer editions of Firefox:

Mozilla recently launched a new version of their web browser called Mozilla Firefox Developer Edition that is specifically geared toward web developers.

I installed it, but I have not found much difference between the regular edition of Firefox and the developer edition. All the tools in the developer edition are also in the regular edition. I want to know what extras the developer edition comes with that the regular edition does not.

What are the differences between the regular and developer editions of Firefox?

The Answer

SuperUser contributors blade19899 and Dave have the answer for us. First up, blade19899:

The Firefox Developer Edition is a modified version of Firefox that is specifically designed for web developers. It also uses a separate profile from the regular version so that running them side-by-side is an option. That does mean that all your add-ons and settings will not be available in the Firefox Developer Edition, but you can use Firefox Sync to get your add-ons and settings synchronized on both versions.

All features in the Firefox Developer Edition will be available 12 weeks before they are available in the regular version of Firefox.

Some features built into the Firefox Developer Edition that the regular version does not have are:


Web IDE allows you to develop, deploy, and debug web apps directly in your browser or on a Firefox OS device. It lets you create a new Firefox OS app (which is just a web app) from a template or open up the code of an existing app. From there you can edit the app’s files. It is one click to run the app in a simulator and one more to debug it with the developer tools. You can watch a video about Web IDE on YouTube here.


Previously called Firefox Tools Adapter, Valence lets you develop and debug your app across multiple browsers and devices by connecting the Firefox developer tools to other major browser engines. Valence also extends the awesome tools built to debug Firefox OS and Firefox for Android to the other major mobile browsers including Chrome on Android and Safari on iOS. So far these tools include Inspector, Debugger, and Console & Style Editor. You can watch a video about Valence on YouTube here.

Web Audio Editor

The Web Audio Editor lets you inspect and interact with Web Audio APIs in real time to ensure that all audio nodes are connected in the way you expect.

You can look through my Q/A on Ask Ubuntu for a more in depth answer: How do I Install the Firefox Developer Edition?

Followed by the answer from Dave:

As I am sure you already know, it currently has these features out of the box:

  • Web IDE – Allows you to develop, deploy, and debug web apps.
  • Responsive Design View – Lets you see how the website will look in different screen sizes.
  • Valence – Debug in any browser (previously called Firefox Tools Adapter).
  • Web Audio Editor – Inspects web audio to ensure all audio nodes are connected as expected.
  • Page Inspector – Examines HTML and CSS.
  • Web Console – See logged info and interact with web pages using JavaScript.
  • JavaScript Debugger – Debugs JavaScript.
  • Network Monitor – See all network requests the browser makes and how long it takes.
  • Style Editor – Edit CSS styles.

You can watch a general video introduction here.

It also includes:

  • Firefox Hello – WebRTC (a tool allowing call and video chat with others from within the browser).
  • Forget Button – Similar to clear history.
  • Eyedropper – Lets you ‘snap’ colors from a web page.
  • Scratch Pad – A stand alone JS console for testing JavaScript snippets.
  • Connect – Lets you connect to a remote device.

As you have likely noticed, some (most) of these features are already available in Firefox or via add-ons right now, and as time goes on, I suspect they will be available as plugins. For example, the Page Inspector, Console, Debugger, and a few more features are already part of the Firebug add-on.

As for changing screen sizes and CSS, I use a tool called Developer Toolbar.

I have used the Firefox Developer Edition as a web developer and designer and it just feels like Firefox with plugins designed to suit a web designer (which is what I think they were aiming for). I am personally more interested in seeing how it develops.

At the moment, it feels very similar to the debugger already built into Chrome and Internet Explorer 11 (although I have not tried every feature yet).

You can also view the Firefox Developer Edition notes for more detail.

Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

Akemi Iwaya
Akemi Iwaya has been part of the How-To Geek/LifeSavvy Media team since 2009. She has previously written under the pen name "Asian Angel" and was a Lifehacker intern before joining How-To Geek/LifeSavvy Media. She has been quoted as an authoritative source by ZDNet Worldwide.
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