Firefox 72 for Developers

This article provides information about the changes in Firefox 72 that will affect developers. Firefox 72 was released on January 7, 2020.

Changes for web developers

Developer tools

Console:

JavaScript debugger:

Network Monitor:

Page Inspector:

Removals

HTML

No changes.

CSS

Removals

SVG

No changes.

JavaScript

APIs

New APIs

DOM

DOM events

Media, Web Audio, and WebRTC

Removals

Security

  • Opting-out of MIME sniffing using X-Content-Type-Options is now also applied to top-level documents if a Content-type is provided. This can cause HTML web pages to be downloaded instead of being rendered when they are served with a MIME type other than text/html. Make sure to set both headers correctly. (Firefox bug 1591932).
  • Dropped the support for HTTP Public Key Pinning (HPKP) because of the low adoption rate and interoperability risk. The Public-Key-Pins and Public-Key-Pins-Report-Only headers are now silently ignored Firefox bug 1412438.

Plugins

No changes.

WebDriver conformance (Marionette)

  • Removed Anon and AnonAttribute strategies from WebDriver:FindElement and WebDriver:FindElements commands (Firefox bug 1587627).
  • Webdriver:TakeScreenshot no longer fails if captured area exceeds upper maximum bound for the canvas width, height, or size (Firefox bug 1590064).

Changes for add-on developers

API changes

Manifest changes

No changes.

See also

Older versions