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This article provides information about the changes in Firefox 61 that will affect developers. Firefox 61 is the current Beta version of Firefox, and will ship on June 26, 2018.

Changes for web developers

Developer tools

  • The Accessibility Inspector has been implemented.
  • The new-look Web/Browser Console UI has been enabled by default (bug 1362023/bug 1347127).
  • In the Network Monitor, clicking Open in New Tab in a POST request's context menu correctly resends the request with the expected POST parameters (bug 1407515).
  • CSS variables now autocomplete with color swatches, allowing you to see exactly what color value is stored in each variable (bug 1451211).
  • You can now drag and drop tabs in the main toolbar of the toolbox to reorder your tools as you wish (bug 1226272).
  • The Network Monitor's toolbar now includes a dropdown menu providing easier access to the 'Copy All As HAR' and 'Save All As HAR' commands, as well as an 'Import...' option (bug 1403530).
  • The Network Monitor's details pane now includes a Cache tab, which displays information about previously cached resources (bug 859051).
  • The Network Monitor's main toolbar now includes a Throttling dropdown, which allows you to throttle your network speed to emulate various different network speed conditions (bug 1349559).
  • The Web console now hides CSS errors by default for performance reasons (bug 1452143).

HTML

No changes.

CSS

SVG

JavaScript

APIs

New APIs

DOM

DOM events

No changes.

Service workers

The "Forget" button, available in Firefox's customization options, now clears service workers and their caches (bug 1252998).

Web Audio, Media and WebRTC

  • The AudioContext() constructor now accepts an optional options parameter of type AudioContextOptions. This lets you configure the preferred latency and/or sample rate for the new context.
  • Firefox now throws the correct exceptions when instantiating an AudioBuffer fails.

WebVR

Canvas and WebGL

No changes.

CSSOM

  • The CSSStyleRule.selectorText property is now fully implemented and no longer read-only (bug 37468).
  • The MediaList interface implementation is now a little closer to the specification. It is not all the way there yet; for example, stringifier attributes haven't been implemented yet (bug 1455807).

HTTP

Networking

  • Firefox 61 and later no longer support using the FTP protocol (that is, URLs with the "ftp://" scheme) to load subresources from within HTML content. FTP is still supported as a top-level URL entered directly into the URL bar or loaded as a standalone document (bug 1404744).

Security

No changes.

Plugins

No changes.

Other

No changes.

Removals from the web platform

Developer tools

Cmd/Ctrl + Shift + O no longer shows/hides DevTools options — use F1 instead (bug 1409456).

HTML

No changes.

CSS

No changes.

APIs

SVG

  • The deprecated (and never properly implemented) SVGViewElement.viewTarget property has been removed (bug 1455763).
  • The following deprecated properties have been removed from SVGSVGElement (bug 1133172):
    • pixelUnitToMillimeterX
    • pixelUnitToMillimeterY
    • screenPixelToMillimeterX
    • screenPixelToMillimeterY
  • The non-standard SVGNumber() constructor has been removed (bug 1455940).

Other

No changes.

Changes for add-on and Mozilla developers

WebExtensions

No changes.

See also

  • Site compatibility for Firefox 61

Older versions

 

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Contributors to this page: chrisdavidmills, Sheppy, fscholz, evilpie
Last updated by: chrisdavidmills,