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Firefox 50, based on Gecko 50, will ship in November 2016. This article provides information about the changes in this release that will affect developers. Nightly builds of what will become Firefox 50 are currently available on the Beta channel. Some experimental features whose release dates are uncertain or undecided are discussed on the page Experimental features in Firefox. Some features described there may be available in Firefox 50.

Items listed here are tentatively slated for Firefox 50; however, they may be held for a future release if testing shows they're not ready by the time Firefox 50 is due to ship. Please keep an eye on this page to stay up to date on the plans for Firefox 50.

Cambios para desarrolladores Web



  • Esquinas con estilos punteados y rayados (dashed, dotted) Border-radiused ahora son mostradas con el estilo especificado en lugar de estilo sólido (bug 382721).
  • El selector pseudo-clase no estándar :-moz-full-screen-ancestor fue removido (bug 1199529).
  • box-sizing: padding-box fue removido, dado que ya no forma parte de la especificación y Firefox era el unico entre los principales navegadores que lo implementaba (bug 1166728).
  • Se removió el prefijo de los tres valores isolate, isolate-override, y plaintext de la propiedad unicode-bidi (bug 1141895).
  • En modo de compatibilidad, la etiqueta de un elemento de lista ahora hereda el tamaño de la lista, como en el modo estandar (bug 648331).
  • Las pseudo-clases :in-range y :out-of-range cambiaron su comportamiento para no coincidir elementos input deshabilitados o de solo lectura (bug 1264157).
  • Se removió el prefijo de la pseudo-clase :any-link(bug 843579).
  • El valor space para border-image-repeat fue implementado (bug 720531).


Herramientas de desarrollador






  • The allowReorder attribute has been dropped and the behavior it was setting is now the default for SVG <switch> elements (bug 1279690).
  • The defer keyword for the preserveAspectRatio attribute on SVG <image> elements has been removed to follow the latest SVG2 specification (bug 1280425).

Drag and Drop API

Pointer Lock API

  • The Pointer Lock API is now unprefixed (bug 991899).
  • Before Firefox 50, requestPointerLock() asked for permission using a doorhanger, and pointer lock would not be enabled until the user granted permission. From Firefox 50, pointer lock is like the fullscreen API: it's granted immediately, but a notification is displayed explaining to the user how to exit (bug 1273351).


Service Workers

  • The WindowClient.navigate() method has been implemented. This method lets you open a specified URL into a client window which is being controlled by the service worker (bug 1218148).



Web Audio API


  • The AlignSetting enum (representing possible values for VTTCue.align) incorrectly previously included the value "middle" instead of "center". This has been corrected (bug 1276130).
  • The non-standard and experimental method HTMLMediaElement.seekToNextFrame() now seeks to the next frame in the media asynchronously, rather than synchronously, and returns a Promise which resolves once the seek is complete.
  • The implementation of HTMLTrackElement has been corrected to allow <track> elements to load resources even if not in a document (bug 871747).

API de batería

Archivos y directorios

Ver también

Versiones anteriores

Etiquetas y colaboradores del documento

 Colaboradores en esta página: frank-orellana, raiosxdxd
 Última actualización por: frank-orellana,