How to Enable the Site-Specific Browser (SSB) in Firefox

Firefox Ssb Feature

If you’ve been champing at the bit for Firefox to catch up to Chrome’s Progressive Web App (PWA) functionality, your wait may now be over. Mozilla has flirted with the site-specific browser (SSB) feature a few times over the years (e.g., Prism), and has supported it on mobile since 2017, but starting with Firefox 73, it seems to be headed towards becoming a core part of the desktop browser.

It’s currently hidden as an experimental feature, but you can still enable and use it in any major Firefox browser version (Nightly, Developer, Beta, stable) before it’s eventually rolled out and becomes available by default.

What does a site-specific browser do?

Firefox Ssb Vs Browser
Firefox browser vs SSB

A site-specific browser essentially creates an “app” out of any website, running in a separate browser instance and behaving like a desktop app. That means some sites can become “first-class citizens,” with taskbar buttons, offline functionality, program-like launching, and other perks that make them more usable than traditional browser-based sites.

Firefox Ssb Chrome Pwa
Chrome browser vs Chrome PWA

It also strips out a lot of your browser’s toolbars, menus, and other UI functionality (the current Firefox implementation as of version 74 especially takes a lot out), limiting you mostly to what the website is programmed to do. Depending on the app or site, this may make your experience smoother, though sites that aren’t built for the SSB/PWA standard may be less usable.

How to enable it

1. Type about:config in the Firefox address bar and click past the warning.

Firefox Ssb Config

2. In the search bar, type browser.ssb.enabled.

3. You should see a Boolean value here, so press the arrow button on the right to switch the value to true.

Firefox Ssb Config Boolean

4. Restart the browser.

How to use it

1. Visit any website you want to use as an app. The Discord chat app is a good example because it already has a desktop app that uses the Electron framework to run web technologies as a program, which means an SSB/PWA version should look quite similar to the existing desktop version.

Firefox Ssb Example Discord No Ssb

2. Click the three dots in the address bar to the right of the URL.

3. Select either “Install this website as app” or “Launch Site Specific Browser.” (This may vary depending on the version you’re using.)

Firefox Ssb Discord Ssb Launch

4. This will install a shortcut to the app directly onto your desktop, allowing you to access it like you would a normal program. If the app already has a desktop version, you can even use them both at the same time if you want.

Firefox Ssb Launch Discord App

5. To manage your installed websites in the future, navigate to the hamburger menu and find the “Site Browsers” or “Installed websites” item (depends on your Firefox version).

Firefox Ssb Hamburger Menu Sites

6. Clicking on a site here will launch it in a new window. In the current stable version (Firefox 74), that’s all you can do, but Developer and Nightly both include an “X” on the right side that allows you to delete the installed website.

Firefox Ssb Nightly Site Manage

The future of web apps in Firefox

Chrome already supports progressive web apps quite well, as Google has basically been creating the standard, so you can play around with it there if you want to see what this feature might look like once Mozilla finishes developing it. Firefox’s version is still relatively rough and behind-the scenes, but if you need to use a PWA/SSB on Firefox right now, it’s there. They’re going to be part of the future Internet, and Firefox’s support for them is an important step forward for the browser.

If you are a Linux user (and not a Firefox user), you can also create your own web apps using Peppermint in Linux or Hermit in Android.

Image credits: Firefox logo, Javascript UI widgets library

Andrew Braun Andrew Braun

Andrew Braun is a lifelong tech enthusiast with a wide range of interests, including travel, economics, math, data analysis, fitness, and more. He is an advocate of cryptocurrencies and other decentralized technologies, and hopes to see new generations of innovation continue to outdo each other.


  1. How is security affected? Through the use of settings and add-ons, Firefox can be pretty will hardened. Does the site-specific “browser” obey the rules of that hardening or does it spawn as a completely open app?

    What is to prevent these site-specific “apps” from containing malware and infecting my PC?

    1. It is simply another instance of the browser. You aren’t losing any protections.
      It is just a new window minus the rest of the interface that comes normally at the top of the browser.
      If you in your browser now select New Window from the menu, and open a site, you nearly have the same thing.

      1. If that’s simply the case, why bother with it? Why not just open into a new window and click the fullscreen icon?

      2. @ian:
        “3. Select either “Install this website as app”
        That does not sound like “simply another instance of the browser”. That sounds like installing a brand new app with all the possible dangers. And as etim says, if it’s only another browser tab/window, why bother with all the “site specific browser” rigmarole?

      3. Good question! It’s basically a website that behaves like a desktop/mobile app in a browser window shell, so a SSB/PWA site has about the same chance of infecting your PC as a normal browser window would. Some SSB/PWA sites have offline functionality, but they don’t automatically get the same direct access to your hardware as an installed program would.

        As for extensions, they’re not currently visible in Firefox’s early implementation (the UI is pretty sparse at the moment), but Chrome currently carries extensions from the main browser to PWA windows, and I know Firefox’s Prism project was able to use some extensions. Given Mozilla’s general stance towards privacy and user control, I’d be pretty surprised if SSB windows don’t have extension support when the final product rolls out.

  2. This option was not available in my Firefox 74 (Linux), but creating it was enough.

    Thanks for the tip, really useful!

  3. Peppermint (Linux) have been doing this for a few releases, they call it ICE (after the release it was first offered in. A very easy way to create SSB’s

  4. Tried this with Twitter on my Linux Mint laptop. With Chromium I have had two instances for my two Twitter accounts, each already appropriately logged in. With Firefox 77.0.1 this scenario does not work, that is, you cannot have two “apps” to same site but with different userid.

  5. Will installed web sites open with Firefox Multi-Account Containers by defalut??

  6. On Linux, does anyone know how to create the sxstem shortcut? in the Post said it creates automatically, however in my Ubuntu 20.04 does not.

    1. Same here with Ubuntu 20.04. :(
      It is working with Chrome, but not with Firefox. Works for me on Windows, though.

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