What's the Best Way to Sync Extensions Across Computers in Firefox?

Dear Lifehacker,
I'm a die-hard Firefox user, but now that Chrome's stable release features extension syncing, I'm really frustrated with my reliable little 'fox. What options do I have if I want to sync my extensions but prefer to stick with Firefox?

Sad About Syncing

Dear Sad Syncer,
We consider extension syncing to be a pretty important part of browser sync, but unfortunately Mozilla's default tool for the job, Mozilla Sync, doesn't sync extensions. We've visited the topic a few times before, but this seems like a good time to revisit your options—and make a friendly video walkthrough. So here are your best options:

Option 1: Sync Your Profile Folder Across Computers with Dropbox

For this section, you can either watch the video below (best watched in fullscreen at 720p) or follow along with the text.


A while back, we detailed how to sync Firefox extensions across computers by syncing your Firefox profile across machines, and we've also addressed slightly newer methods. Those guides are a little outdated, though, and you'll likely have a lot more luck using the much-beloved file-syncing tool, Dropbox. Assuming you have Dropbox installed on all the computers you're running Firefox on, you can sync your Firefox profile and extensions in two ways:

  1. Add your Firefox profile folder (which contains all your extensions, bookmarks, and pretty much every other piece of data unique to your individual Firefox installation) to your Dropbox folder.
  2. Run Firefox Portable from your Dropbox folder.

Either method has its pros and cons. Firefox Portable is the most pain-free option, but it will only work with Windows computers. Syncing your profile folder using Dropbox takes a little more work to set up, but it works across platforms, so I can sync my extensions and profiles between Windows, Mac, and Linux computers. Here's how the setup works:

To sync Firefox Portable:

What's the Best Way to Sync Extensions Across Computers in Firefox?

Step One: Download Firefox Portable and put it somewhere inside your Dropbox folder.
Step Two: There is no step two. Assuming you've got Dropbox installed on all the computers you want to use your synced Firefox installation on, you're good to go.

To sync your Firefox profile folder across platforms:

Step One: Open Firefox's Profile Manager and create a new profile. If you're on a Windows machine, just type Win+R, then paste firefox.exe -p into the Run box and hit Enter. On OS X, I've always found the easiest way to use Profile Manger is just to install the ProfileSwitcher extension. (In fact, if you're using multiple Firefox profiles for more productive browsing, it's a must-have extension.)

Step Two: Once you've opened Profile Manager, click the Create Profile button, give your profile a name (I chose Synced Firefox), then click the Choose Folder button. Point it toward any folder inside your Dropbox folder (I went with something like Dropbox\Syncing\Synced Firefox, but anything you choose will do. Once you're done, click Finish.

Step Three: Now you've got one Firefox profile syncing to your Dropbox folder. After you've let it finish syncing all the files to the Dropbox server, your next step is to set up new profiles on your other systems that point back to the same folder in your Dropbox account. So fire up Profile Manager on the computer(s) you want to sync with and run through steps one and two on those.

The good: Now any extension you add to one Firefox installation will automatically sync to your other installs. And since you're syncing your entire Firefox profile folder, you're also syncing everything else—like browser sessions, history, bookmarks, and everything else that lives in your Firefox profile folder.

The bad: This method works really well, but you may occasionally run into hiccups and sync conflicts if you have multiple synced browsers running at the same time. You'll have better luck if you close Firefox on one machine before opening it on another.

Option 2: Set Up Pseudo-Syncing with the Add-on Collector

Mozilla's Add-on Collector is a Firefox extension that allows you to create collections of extensions available on the official Firefox Add-ons site. It works like this:

What's the Best Way to Sync Extensions Across Computers in Firefox?

After creating an account on the Add-ons site, you can search for and add any extensions to a new collection—for this example, I've named mine Extensions I want Synced. Then you'd install the Add-on Collector on every browser you want to sync extensions between and give the Add-on Collector your Mozilla username and password. You'll see a new Subscriptions tab in Firefox's Add-on manager, which will list all the extensions you've added to that collection. Every time you install a new extension you want synced, just make sure you add it to your collection.

The good: Add-on Collector will automatically check your collection for new add-ons and display notifications when you've got "unsynced" extensions; it also rounds them all up in one place so you can quickly install them without having to hunt them down.

The bad: Unfortunately you still have to manually install each extension.

Hope that helps!


P.S. Got a method for syncing extensions that works for you? Share it in the comments.