Firefox 101 Stable: security fixes and classic download behavior restored

Mozilla plans to release Firefox 101 to the Stable channel on May 31, 2022. The new version of the open-source web browser is a smaller version that includes some improvements and security fixes.

Mozilla has also released updates to other Firefox channels. Firefox 91.10.0 ESR, Extended Support Release and Firefox 101 for Android have also been released. All browser development channels have been updated alongside this: Firefox Beta and Developer have been moved to version 102, and Firefox Nightly to version 103.


  • Firefox 101 Stable is a security update that addresses browser security issues.
  • Firefox 102 is the next release from ESR. It will be released next month.

Firefox 101.0 Download and Update

firefox version 101

Firefox 101 is already available. The browser’s built-in update system may not pick up the update at the time of writing, but it should be available later May 31, 2022. If you’re reading this after May 31, you should receive the update. update immediately when you run a check it.

Select Firefox Menu > Help > About Firefox to view the installed version of the browser. Firefox runs an update check when the window opens to download and install any update it finds.

Here are the links to the official download repositories.

New features and improvements in Firefox 101.0

Return of the classic download prompt

firefox open or save files

The big new improvement in Firefox 101 is the one not highlighted in the official release notes. Mozilla changed the browser’s download behavior in Firefox version 97, which it released in January 2022.

Firefox displayed a prompt to the user, giving them options to open or save the file. The new download prompt copied the behavior of Chromium-based browsers; this meant that Firefox started downloading immediately.

Although there was an option to change the behavior by enabling “always ask you where to save files” in the preferences, this did not replicate the full functionality of the classic download prompt.

Now with Firefox 101 comes an option to restore the old prompt:

  1. Load about:preferences in the Firefox address bar.
  2. Scroll down to the Applications group on the page.
  3. Switch the default “save files” option to “ask whether to open or save files” on the page.

Other Changes

  • Mozilla notes that Firefox users can assign custom actions to any “unconfigured MIME type” after the download is complete.
  • Firefox supports the use of multiple microphones during video conferences. The browser supports switching between microphones, provided the conferencing service provider supports the feature.
  • Firefox for Android supports using a magnifier for forms on Android 9 and later, which improves the usability of forms in the browser.

Developer Changes

  • Sites can use the prefer-contrast media query to determine if a user has requested higher or lower contrast.
  • Small, large and dynamic window sizes have been introduced
  • Constructable style sheets are now supported.
  • AV1 codec settings are now parsed correctly in media support queries.
  • The WebDriver BiDi protocol is enabled by default in this version of Firefox
  • Several Manifest V3 APIs and changes added:
    • Added scripting API for add-on developers, “which provides functionality to run a script, insert and remove CSS, and manage the registration of content scripts”.
    • Added action API, “which carries over the functionality of the browserAction API in the Manifest V3 extensions”.
    • Added “host_permissions” manifest key, which is available for Manifest V3 extensions.
    • The “background” manifest key property “persistent” can be set to false under preference control: for Manifest V2, the extensions.eventPages.enabled preference and in Manifest V3, the extensions.manifestV3.enabled preference.
    • The content script execution environment has changed for Manifest V3 extensions.

Company changes

Known issues

none listed.

Security updates/patches

Security updates are revealed after the official release of the web browser. You find the information published here after release.


Firefox 102 will be released on June 28, 2022, according to the release schedule; this also marks the launch of the new base version of Firefox ESR. Firefox ESR 91.x will reach end of support on September 20, 2022.

Firefox extension reviews and news

Recent Firefox news and tips

Additional information/sources


Firefox 101 Stable: security fixes and classic download behavior restored

Article name

Firefox 101 Stable: security fixes and classic download behavior restored

The description

Firefox 101 is a security update for the Firefox web browser, which also restores the browser’s classic download behavior as an option.


Martin Brinkman


Ghacks Technology News



Previous Choose your preferred Teams download location after the next update
Next Diablo Immortal PC Download: How to Play the Open Beta