Shared knowledge for the Open Web
Get Web technology news from Mozilla, get help from other developers, and more!
Pixel Perfect is a Firefox extension that enables web designers to overlay a web page with semi-transparent images (layers). The designer can then tweak the page’s content until it exactly matches the layer. This extension was originally introduced for Firebug back in 2008 but has not been maintained for several ...
Every tool starts with an idea: “if I had this, then I could do that faster, better, or more easily.” The Firefox Developer Tools are built atop hundreds of those ideas, and many of them come from people in the web development community just like you. We collect those ideas ...
In a web page, every element is rendered as a rectangular box. The box model describes how the element’s content, padding, border, and margin determine the space occupied by the element and its relation to other elements in the page. Depending on the element’s display property, its box may be ...
Firefox OS is an operating system built on top of the Firefox web browser engine, which is called Gecko. A browser app on Firefox OS provides a user interface written with HTML5 technology and manages web page browsing using the Browser API. It also manages tabbing, browsing history, bookmarks, and ...