Mozilla Firefox 31 is a web browser developed by Mozilla Foundation , available for download in full install version for Windows platforms from legacy sources. This version of Firefox was officially released on 2014-07-22 for public access and a brief summary of important updates and change log pertaining to this edition can be read below.

Though Firefox 31 was released with fixing of ability to select partial link text from context menu, there are many known issues in the previous build remain unsolved like slow shutdowns showing another instance of the browser process, incorrect PDF component rendering in the native viewer, black screen of Google Maps Street in Windows XP and inability to work in Citrix receiver.

In the HTML elements changes WebVTT and CSS3 variables has been implemented and enabled. There are many new functionality additions including adding search field in new tab, native handling by firefox for .ogg  and .pdf files, blocking malwares from downloaded files and safe http header for parental control.