Tip: Use Firefox for Web Apps

Posted on January 10, 2021 by Paul Thurrott in Mozilla Firefox with 25 Comments

A reader tipped me off to an experimental Firefox feature that lets it work as seamlessly with PWAs as does Google Chrome, Microsoft Edge, and other Chromium-based web browsers.

What’s odd about this feature is that Mozilla originally innovated the ability to run webpages and apps as if they were native applications using a technology called Prism that has long since been stripped out of that browser. But as web apps have grown more sophisticated in more recent years, Chrome and other browsers have picked up similar capabilities, and Google has an entire platform, called Chrome OS, dedicated to running these apps outside of the normal browser container.

I’ve long wondered why Mozilla dropped Prism and discontinued the ability to run web apps as if they were native apps. But it turns out that the firm didn’t give up completely. The mobile versions of Firefox have been able to create apps from webpages since 2017. And Mozilla started testing a similar approach for supplying this functionality on desktop almost a year ago.

I can’t explain why I wasn’t aware of this (at least the desktop bit), but it’s called Site Specific Browser (SSB) and it’s here now for those interested in testing it.

“An SSB is an application with an embedded browser designed to work exclusively with a single web application,” Mozilla explains. “It doesn’t have the menus, toolbars, and accouterments of a normal web browser. Some people have called it a ‘distraction-free browser’ because none of the typical browser chrome is used. An SSB also has tighter integration with the OS and desktop than a typical web application running through a web browser.”

To use SSB with Firefox, you must be running Firefox 73 or newer—which won’t be hard, as the latest version is 84—and you have to enable it first. To do so, type about:config in the Firefox address bar and click-through the warning. Then type browser.ssb.enabled in the address bar to find the feature. It is currently set to false. Use the toggle button on the right to change it to true and then restart Firefox.

Now, you can run any webpage (and not just PWAs and other web apps) as if it was an app. To do so, navigate to the webpage or web app you wish to use, then click Page actions (“…”) in the address bar and choose “Use This Site in App Mode.”

When you do, the page/app will appear as a standalone app window, and shortcuts will appear on the desktop and in the Start menu. You can pin this app to the taskbar or to the tiles area of the Start menu, just as with any other app.

To manage the apps you’ve installed this way, open Firefox, open the (hamburger) menu, and choose “Sites in App Mode.” You can uninstall any app here by choosing its Uninstall (“x”) button.

Thanks to SherlockHolmes for tipping me off to this feature.

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Comments (25)

25 responses to “Tip: Use Firefox for Web Apps”

  1. winner

    I use Firefox for just about everything.

  2. blinkertoon

    Hi. Have been looking for this feature for quite some time, and also found this solution. However, I'm using FF Dev 89.0b12 and my SSB option doesn't look the same (instead has boolean, number, string radio buttons). Also, possibly as a result, I don't have the three dot menu with option to "Use this site in App mode" or the "Sites in App mode" option under the burger menu.

    Any help much appreciated!


    • blinkertoon

      Quick update: have been able to add the "True" SSB option (by clicking plus to the right of the existing one mentioned above), only the "Page actions (“…”)" menu is still not present, or the applist list under the burger menu :(


      • bradavon

        Looks like they've removed it in FF89 :( -


        • searia

          For anyone looking for a workaround: there's an add-on that does this called Progressive Web Apps for Firefox

  3. Stoicjim

    I did this for the Facebook site but lost my "Fluff Busting Purity" addon to manage it.

  4. waethorn

    In reply to proftheory:

    It's slow, buggy, and still to this day has memory issues, probably because it doesn't use any existing desktop environment API's for its UI layout. Even Linux DE builders only tolerate it because Mozilla doesn't make it easy to integrate into the DE skin while other browsers do it with alacrity. The open-source nature of it is suspect due to the way the company is structured, they still haven't lived down the Mr. Robot adware event, and the company has now stated that Internet freedom isn't allowed if you offend someone with your opinion, although they previously eluded to this with their recent corporate code of conduct changes.

  5. adinas

    Once I realized they support totalitarianism I stopped using them. They seem more interested in politics than making good software

  6. madthinus

    Mozilla is somehow anti PWA's, but I don't think it has anything to do with the feature, more to do very limited resources.

  7. sherlockholmes

    Its still a little buggy. But its a start.

  8. clowg

    I've just tried this in 84.0.2, and find it will only allow one 'App Mode' window to be created. After creating the first one OK, when I try the 2nd one nothing happens.

  9. jdawgnoonan

    Firefox should expand on this. On Linux running a web app in that mode does not make it available as an app except for from within the browser.

  10. griszimek

    Sadly, they've just announced to remove this feature? And that they have no plans to support PWAs at all in the future?


    • ianhead

      In reply to Griszimek:

      Oh man. What a depressing thread. After reading about Mozilla's continued financial problems, seemingly largely caused by their increased focus on social initiatives and fruitless side ventures at the expense of resources devoted to their flagship browser, it reads like one more very avoidable nail in Firefox's coffin.

      • Username

        In reply to ianhead:

        unlike other browsers, Mozilla doesn’t have means to have its expenses offset by cross-subsidies. Hence, relying on donations and “increased focus on social initiatives and ‘fruitless’ side ventures”.

        (BTW. Masquerading websites as applications is daft. Hopefully, a short-lived brain fart.)

        • omen_20

          In reply to Username:

          If daft means modern or the future in your mind, then yeah.

          Windows 10 works very well with PWAs and having them burried in a browser's tabs, instead of being top level in the task bar is just terrible UX.

          • LT1 Z51

            In reply to Omen_20:

            I don't get PWA's or even "apps" on my phone that are just websites (with no additional functionality).

            I guess I still have expectations that Software is USEFUL and not just another way to skin something that's already garbage.

            • Paul Thurrott

              Um. Web apps are apps. They can be great, bad, or indifferent, but them being web apps doesn't preordain them to be garbage.
  11. dxtremebob

    When SSB application shortcuts are saved to the Desktop, task bar, etc, clicking them invokes the app only when Firefox is already running.

  12. cyclequark

    I have been looking to do this for Twitter. For reasons that I do not understand Twitter misbehaves in Chrome and Edge for me, so I run Firefox, but I would move to Edge if I could run Twitter is a standalone mode.

    • IanYates82

      In reply to cyclequark:

      I find the Twitter app works OK.

      Although I see people using more and more extensions for Twitter (like BotSentinal) and can see why you'd want it to run in a browser. When I have tried it, I don't think I have issues with it in Edge. I'll have to try it more to report back :)