Firefox 67 for developers

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This article provides information about the changes in Firefox 67 that will affect developers. Firefox 67 is the current Beta version of Firefox, and will ship on May 14, 2019.

Changes for web developers

Developer tools

No changes.

Removals

HTML

  • The target="_blank" attributes on the <a> and <area> elements now automatically implies the rel="noopener" set on those elements. If you do not want that behavior, set the newly added rel="opener" attribute in addition to the target="_blank" (bug 1522083).

 Removals

CSS

Removals

SVG

No changes.

Removals

JavaScript

Removals

APIs

No changes.

New APIs

DOM

DOM events

CSS

  • Add support for CSS prefers-color-scheme media feature (bug 1494034).

Service workers

Media, Web Audio, and WebRTC

  • Calling RTCPeerConnection.addTrack() without specifying any streams to which to add the new track now works as expected: it adds a streamless track to the connection. Each peer is responsible for managing the association between the track and any stream on its end (bug 1231414).

Canvas and WebGL

Removals

  • The deprecated ShadowRoot.getElementsByTagNameShadowRoot.getElementsByTagNameNS, and ShadowRoot.getElementsByClassName properties (part of Shadow DOM v0) have been removed (bug 1535438).

Security

No changes.

Removals

Plugins

No changes.

Removals

Other

No changes.

Removals

Changes for add-on developers

API changes

No changes.

Removals

Manifest changes

No changes.

Removals

See also

Older versions

Document Tags and Contributors

Last updated by: yisibl,