Firefox 114 for developers

This article provides information about the changes in Firefox 114 that affect developers. Firefox 114 was released on June 06, 2023.

Changes for web developers

Developer Tools


No notable changes.


  • The :lang() pseudo-class now uses string-matching semantics (including * wildcards) for matching language codes rather than prefix-matching semantics. Additionally, comma-separated lists of languages are now supported for matching multiple languages (Firefox bug 1121792).
  • The -webkit-text-security property that lets you replace characters with shapes is now supported. You can now control the rendering of text security using this property (Firefox bug 1826629).
  • The infinity and NaN constants are now supported inside the calc() function (Firefox bug 1830759).





WebDriver conformance (WebDriver BiDi, Marionette)

WebDriver BiDi

  • Added support for the commands input.performActions and input.releaseActions, which can be used to emulate user input for interacting with elements on web pages. Similar to Marionette all the available input sources of the WebDriver specification are supported, which are key, pointer, and wheel (Firefox bug 1832380).
  • Added support for custom browser to client messages, which allows to send a script.message event from within a script formerly installed via script.addPreloadScript (Firefox bug 1824187).
  • Added support for the serializationOptions parameter for script.evaluate and script.callFunction to customize the RemoteValue serialization (Firefox bug 1824953).
  • Fixed an issue where both the script.evaluate and script.callFunction commands did not include the stack trace and failed to properly build the exception details for a rejected Promise (Firefox bug 1829630).
  • Fixed an issue where the browsingContext.domContentLoaded and browsingContext.load events did not report the correct url, when the page defined a <base> meta tag (Firefox bug 1825634).


  • Fixed an issue where the command WebDriver:GetComputedRole didn't properly return the WAI-ARIA roles (Firefox bug 1822112).
  • Fixed an issue where modifier keys were not reset when they were used again within the same WebDriver:ElementSendKeys command (Firefox bug 1776190).

Changes for add-on developers


Older versions