Firefox Developer Edition is a new version of the popular browser Mozilla, focused on web developers.

In recent years the most popular browsers have built-in tools that allow viewing and editing the source code of web pages. This tool is very useful for web developers since it allows them to localize errors easily, edit the web page on the fly, and see immediate results of the changes.

Firefox Developer Edition is a standard web browser so that we can browse the Internet in the usual way. Still, it has the peculiarity that it includes many tools that facilitate web developers' work. Some of these tools are:

• Valence : this tool allows us to debug different browsers on different devices. For example, we can debug a web page on Safari on iOS or Chrome on Android. This allows connecting the mobile device to the computer and making changes to the page source code using Firefox. These changes will be reflected in the connected mobile devices. This tool is in a testing phase, so it is not recommended to work with it consistently.
• Responsive design : thanks to this view, it will not be necessary to install any plug-in to check how the page is viewed in many resolutions. This way, we can see if the responsive design adapts perfectly to the maximum number of possible resolutions.
• Page Inspector : this panel displays information about the elements that make up the web page. We can see and modify the HTML and CSS code on the fly. For example, if we select a CSS class, we will see highlighted on the web all the elements that make use of that CSS class. The same happens with the HTML code; when we open the “Inspector Page” panel and place the cursor on top of an HTML element, this element will be highlighted on the page's design.
• Web Console : this panel shows the errors and warnings messages generated by the web page that we are visiting and organizes them into categories so that we can see the corresponding errors to CSS, Javascript, Network, etc. we can also interact with the elements of the web by typing javascript code on the console. We can call the method of an object or use jQuery to list a series of items. Anything we can do on Javascript can be performed directly on the “Web Console.”
• Network Monitor : here, we can see all the requests performed by a web page and explore the headers of the same. This view is very useful to know exactly how many external elements are loading a web and if it is necessary to reduce the number of elements. We can filter the requests by type: HTML, CSS, JS, Image, Sources, Multimedia, and others.

These are just some features that this new version of the Firefox browser presents. Sure many web developers will be happy with this version and will make Firefox Developer Edition their default browser.