Firefox 98 for developers

This article provides information about the changes in Firefox 98 that affect developers. Firefox 98 was released on March 8, 2022.

Changes for web developers




No notable changes




  • The deprecated WebVR API is now disabled by default on all builds (previously it was enabled on Windows, macOS, and all nightly/dev builds). It can be re-enabled in about:config by setting dom.vr.enabled to true (Firefox bug 1750902).

WebDriver conformance (Marionette)

Changes for add-on developers

  • Web extensions using webRequest were started early during Firefox startup. This has changed to only trigger early start-up for extensions using webRequest blocking calls. Non-blocking calls no longer cause the early startup of an extension. (Firefox bug 1749871)
  • cookieStoreId added to userScripts.register. This enables extensions to register container-specific user scripts (Firefox bug 1738567).

Older versions