Firefox 54 for developers

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Firefox 54, based on Gecko 54, will ship in June 2017. This article provides information about the changes in this release that will affect developers. Nightly builds of what will become Firefox 54 are currently available on the Nightly 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 54.

Items listed here are tentatively slated for Firefox 54; however, they may be held for a future release if testing shows they're not ready by the time Firefox 54 is due to ship. Please keep an eye on this page to stay up to date on the plans for Firefox 54.

Changes for Web developers

Developer Tools

  • Avoid scrolling latency on highlighters given by APZ (bug 1312103).
  • Added transferred size to network request summary and performance analysis view (bug 1168376).

HTML

No change.

CSS

  • inline-block with a display:block <input> child element has a wrong baseline (bug 1330962).
  • Removed -moz prefixed versions of isolate, isolate-override, and plaintext values of unicode-bidi property (bug 1333675).
  • -moz-appearance:none should make checkboxes and radios be non-replaced elements (bug 605985).
  • [css-align] Implement the updated spec language for interactions between "align-items" & "align-self", "justify-items" & "justify-self" (bug 1340309).
  • clip-path now supports basic shapes (bug 1247229).

JavaScript

Interfaces/APIs/DOM

DOM & HTML DOM

Canvas

No change.

WebGL

No change.

IndexedDB

No change.

Service Workers

No change.

WebRTC

No change.

New APIs

No change.

Others

No change.

MathML

No change.

SVG

No change.

Audio/Video

No change.

HTTP

No change.

Networking

No change.

Security

No change.

Changes for add-on and Mozilla developers

Interfaces

No change.

XUL

No change.

JavaScript code modules

No change.

XPCOM

No change.

Other

No change.

See also

Older versions

Document Tags and Contributors

 Contributors to this page: Masayuki, chrisdavidmills, Sebastianz, yisibl, arai, ziyunfei
 Last updated by: Masayuki,