Nightly Logo

Last chance to migrate your legacy user data

If you are working on transitioning your add-on to use the WebExtensions API, you have until about mid-October (a month before Firefox 57 lands to allow time for testing and migrating), to port your legacy user data using an Embedded WebExtension.

This is an important step in giving your users a smooth transition because they can retain their custom settings and preferences when they update to your WebExtensions version. After Firefox 57 reaches the release channel on November 13, you will no longer be able to port your legacy data.

If you release your WebExtensions version after the release of Firefox 57, your add-on will be enabled again for your users and they will still keep their settings if you port the data beforehand. This is because WebExtensions APIs cannot read legacy user settings, and legacy add-ons are disabled in Firefox 57. In other words, even if your WebExtensions version won’t be ready until after Firefox 57, you should still publish an Embedded WebExtension before Firefox 57 in order to retain user data.

When updating to your new version, we encourage you to adopt these best practices to ensure a smooth transition for your users.

10 comments on “Last chance to migrate your legacy user data”

  1. Allan Rho wrote on

    What’s the use of retaining my addon user data if the WebExtensions framework can’t even support what’s needed for powerful and worthy extensions to continue working?

    *Ahem, DownThemAll. Ahem, TabGroups.

    1. Nina So wrote on

      I feel the same as well. What has drawn me to Firefox is the level of customization not found in any other browser thanks to how good and capable its extensions are. Now, those extensions will soon cease to function. What will stop me now from switching to another browser? Sad.

    2. Elias Rodriguez wrote on

      I use those two extensions too and too bad for us. Mozilla thinks Google Chrome extensions are better for us users.

      Guess what? I can only see one or two WebExtensions-based extensions in the list of Top Rated and Most Used Firefox extensions. If Mozilla’s overlooking that, I believe Firefox is more than willing to overlook us loyal Firefox users. smh.

  2. Linda wrote on

    Woke up this morning and every tile I had is GONE! What’s happening? This is awful.

    1. Amy Tsay wrote on

      Hi Linda, which add-on are you using? Also, you can post questions about your add-ons here:

  3. DeveloperChris wrote on

    The most consistent comment I read on these blogs lately is why is Mozilla killing firefox? As a web developer I have clung to firefox like grim death. Now with a wall [legacy] flags in about:addons I must say like the other developers in my team I am finally ready to switch to Chrome.

    Its been a great ride while it lasted but the end is nigh. sigh…

  4. Melchior wrote on

    The LOSS/SCRAPPING of the XUL/XPCOM extension system is

    I AM am running 20 Firefox extensions of which:
    [Legacy Extensions] = 12
    [Web Extensions] = 8

    most of which CANNOT be ported because Web Extension API IS INFERIOR TO
    the customizations possible with XUL/XPCOM…

    I moved to ESR v52.x a whole ago..
    and will keep with it till ESR moves to v59 next year..
    then I am moving to Waterfox a fork of Firefox because HE will be keeping XUL support!!

    MOZILLA has LOST their minds..!

  5. Julio Basombrio wrote on

    No lo hagan. Para mi se terminó FF en tal caso.
    Qué les sucede?
    Están por convertirlo en comercial?

  6. Pete wrote on

    In a far less articulate manner I just want to AGREE with several of the above and say – Firefox – you have successfully Screwed users like me who have tried to find something in the Chrome – faceless – model browser but preferred the ability to customize LO ABSOLUTELY NEEDED IT IN MY WORK AND LIVELIHOOD AND HAVE NOT been following your grand design to all of a sudden update my browser so that it is as useless to me as those others in your competition precisely because I WANT the \ADDons l;ike Session manager to Save my 5 open windows and 70 open color coded tabs that I am using in my research withount making me save each link to bookmarks or read every single line of every relevant page before going to sleep at 6 am – this research has been going on for years and now blip – you list NO addons avallable with the search of Sessions or Tabs or any of the functionality that I use for hours every day. I am really upset – pissed off – not happy with you. and no warning to the average user – nope – just flip the switch on one day and out of a job – thanks a bunch. engineer dweebs.;.

  7. kstev99 wrote on

    I’ve used Firefox since it rose from the ashes of Netscape years ago. It’s a shame that Mozilla has decided to hasten the demise of a once great browser by ignoring its user base. I’m afraid that is will soon meet the same fate as Netscape.