What is Firefox FlyWeb?

Martin Brinkmann
Jul 26, 2016
Updated • Jun 25, 2017
Firefox, Firefox add-ons

If you are running Firefox Nightly, the cutting edge version of the Firefox browser, you may have noticed a new system add-on that goes by the name FlyWeb already.

FlyWeb, just like Pocket or Hello, are so-called system add-ons. The main difference to regular add-ons is that they get installed with the browser and not by the user.

System add-ons give Mozilla better options when it comes to delivering updates to these features, as they are handled separately from browser updates.

Core issue with these add-ons is that they are not listed in the add-ons manager, and that users don't have full control over them. So, most users probably don't even know that system add-ons exist, and those who do, may have no clue how to disable them if they don't need the functionality.

Firefox FlyWeb

FlyWeb is linked to Mozilla's big Internet of Things push. The main idea behind the feature is to get phones to interact with electronic devices directly instead of using the cloud for that.

Meet FlyWeb. FlyWeb is a very simple idea at its core. Instead of phones interacting only with the cloud, they can discover and interact with electronics around them that are running empty web clients, such as TV's, projectors, game consoles, etc. The electronics come to life when connected to phones. The key here is that either the phones serve web apps to these electronics, or the electronics serve web apps to the phones.

The description alone may raise an eyebrow or two. First, Mozilla mentions phones specifically yet  FlyWeb is in Firefox Nightly for the desktop.

Note: The information are puzzling at this point. The about:support page lists FlyWeb as enabled regardless whether you set dom.flyweb.enabled to true (enabled) or false (disabled).

Considering that Firefox Nightly is the main development version of Firefox, this is somewhat understandable.

Second, and that is probably the big one, it raises the question why something like that is needed in Firefox.

Mozilla has an answer for that. Basically, it is the browser that the company wants to use to discover and interact with electronics. This works best obviously with mobile devices but is not limited to that.

Here is a introduction video of FlyWeb

Disable FlyWeb

As mentioned earlier, FlyWeb is only available in Firefox Nightly currently. It seems enabled by default, but we don't know yet when FlyWeb will be moved to other Firefox channels. Also, it is unclear if the feature will be enabled on those channels by default.

If you have no need for FlyWeb currently, you may want to disable the feature in Firefox. Good news is that you can do so easily in the following way:

  1. Type about:config in the Firefox address bar and hit enter.
  2. Confirm that you will be careful if the warning prompt is displayed.
  3. Search for dom.flyweb.enabled.
  4. Make sure the preference is set to false.

The preference does not seem to change the status of FlyWeb currently. If you disable the feature and check about:support, you will still see it listed as enabled.

flyweb firefox addon

To get rid of it completely right now, you may delete the add-on on the local hard drive. Note that it may come back at a later point in time when Firefox updates.

  1. Go to the Firefox installation directory on your computer, e.g. C:\Program Files (x86)\Nightly\browser\features on Windows 32-bit.
  2. Locate flyweb@mozilla.org.xpi.
  3. I suggest you back up the add-on first.
  4. Select the add-on and delete it.

Additional information is provided on Mozilla's Wiki, and the main FlyWeb tracking bug.

What is Firefox FlyWeb?
Article Name
What is Firefox FlyWeb?
FlyWeb is a new system add-on in the Firefox web browser designed to discover and interact with electronic devices directly without using the cloud.
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  1. Дмитрий said on August 3, 2016 at 7:18 am

    Don’t worry guys, AFAIK Mozilla will stop shipping Hello since 49, maybe they will abandon this FlyWeb eventually, too.

  2. Kuromi said on August 3, 2016 at 1:30 am

    I cannot say i totally dislike whole idea or i hate system addons (because these addons created to make possibility to quickly update functionality within Firefox without complete update of browser) but i have rather hard time understanding WHAT exactly will FlyWeb do? The only understandable example is Google Chrome + Chromecast device. You go to Youtube, push button “cast”, your browser connects to external device (chromecast) and tell it to play this video. Ok.
    Its works fine, as user of Chromecast i can say that. But with WHICH devices Mozilla going to communicate? They dont have any ecosystem tot talk with anyway.

  3. WildcatRay said on August 1, 2016 at 12:39 pm

    The point should be that the developers need to serve the users and not their own personal desires.

    Like Hello, FlyWeb is a solution in search of a problem or, if you prefer, a product in search of a market.

    As a longtime user of Nightly, I have seen way too many patches get landed that “fixed” things that simply were not problems. It is as if the patch writers wanted to make a name for themselves by landing as many patches as possible without regard for whether any of those patches actually fixed a bug or improved the browser.

    I agree with Martin on his point of how many users will actually use any of these addons. Likely, only a very small minority of Firefox users will even try, let alone become “users”.

  4. mythsmith said on August 1, 2016 at 9:35 am

    The reason why this isn’t an optional addon is that if it were optional, it would be useless. The whole point is being able to interact with the environment without the need to install anything – except the browser itself. If you need to install an addon, it looses most of its appeal.

    1. Martin Brinkmann said on August 1, 2016 at 12:22 pm

      Would not it be better for users to install the add-on if they want to interact with devices`? Just like Hello or Pocket, this is something that only a minority of Firefox users will use. I understand the reasoning behind making it available to all, as it may increase the userbase significantly.

      Still, that userbase is considerably smaller than the group of Firefox users who has no use for the feature.

      1. mythsmith said on August 1, 2016 at 3:02 pm

        Why did facebook implement a video chat nobody wants? Because if they implement it, people will start depending on it and possibly today’s minority will be tomorrow’s majority.
        I will probably never use that feature in the next 2-3 years. But I like the idea Firefox is working on it, pushing a this feature to a huge (unconscious) userbase. Because if they don’t do in that way, someone else will, and in a closed way. Apple, or Google, or Microsoft will implement their own closed way of interacting with the environment – embedded in the OS – with the result of discriminating even more between ecosystems.
        If firefox succeeds doing that in an open way, everybody will benefit from it, even those who will never even know this feature exists. Proprietary empires will be forced to adopt an open standard, instead of using IOT to divide users even more.

  5. WildcatRay said on August 1, 2016 at 3:04 am

    I wonder why it is mozilla won’t offer these system addons through addons.mozilla.org as they properly should? Are they afraid that they will very quickly find out that users just don’t want such crapware bloating their browsers?

  6. wonton said on July 28, 2016 at 3:39 am

    cyberfox has options to remove system addons on browser install hope they add this rubbish too :( why mozilla why

  7. Uhtred said on July 27, 2016 at 9:10 pm

    Why can’t mozilla simply give you the option to install default settings (recommended by them) or install custom (user decides what to include)… if it did that for each browser upgrade it would put an end to a lot of complaints about what its doing… adding just that bit of choice… and the multitude of users who don’t care or are not technically minded can simply install without any fuss.

    I’m wondering about this flyweb tho, the functionality could be very useful, but, after making a big deal about promoting “privacy” on the web, they’re potentially opening up channels of communication with a myriad of devices, and not allowing users easy control over that… very strange, one might almost say it was a microsoftism

  8. PeaKr said on July 26, 2016 at 7:50 pm

    Remember when people used to flock to Firefox in droves, when it was cool and edgy.

  9. Tony said on July 26, 2016 at 6:24 pm

    This should not be integrated into the browser by default (and neither should Pocket or Hello). Add-ons should be add-ons: in other words, add them on if you want, leave them out if you don’t want.

    Extra code = more surface for exploits, bigger memory footprint, slower to load, more bugs.

    Mozilla needs to remember KISS: Keep it Simple, Stupid.

    1. gh said on July 27, 2016 at 1:02 am

      Tony, I agree, but… although it might be “an undocumented hassle” to leave ’em out, we can in fact do so (pocket, reader, flyweb) because they are shipped as external components.

      I don’t believe we can reasonably expect / demand that mozilla not “bundle” these toys inside the installation package. Perhaps we might try to demand the installer will obtain “informed consent such that user is asked “would you like fries with that? Howabout a pocket?”, in the course of installing (or upgrading) “web browser”.

  10. ak said on July 26, 2016 at 5:11 pm

    Another way is to use “Simple Add-on Manager” add-on. You can enable/disable add-ons including system add-ons.

    1. ams said on July 27, 2016 at 7:38 am

      What, and trust the settings behind those little checkboxes will be respected? Trust that tomorrow’s update won’t silently reset the settings (mozilla pulled that sh*t with HealthReport telemetry. Initially it was opt-in. When too few people opted in, a later update reset the pref so that everyone was opted-in EVEN if you had previously opted out. I’m still pissed toward mozilla about that.)

  11. intelligencia said on July 26, 2016 at 3:16 pm

    Hello Everyone:

    I would say that I am moderately Internet Savvy BUT (using common sense) this whole flyweb seems to be another way where one’s privacy can be compromised. To me the system seems to be Too open for intrusion by hackers!
    Anyway, having said that, My favorite browser is STILL Firefox!


  12. happysurf said on July 26, 2016 at 9:43 am

    Martin, there is a better way for disable the system add-ons:
    > about:performance > Performance of Add-ons > show all.
    From the list is easy disable the system add-ons and in addition is possible understand which extension slow down Firefox..

    1. gh said on July 27, 2016 at 12:39 am

      The approach I would choose is this:

      1) Yes, visit about:config and set dom.flyweb.enabled=false and, additionally

      1a) carefully edit the json string stored in the prefkey named “extensions.xpiState” to remove the reference to flyweb (need to lookup the GUID string for its xpi, I don’t know it offhand)

      2) exit firefox, browse to the installed directory and rename or delete the flyweb xpi file

      Failure to remove the reference within extensions.xpiState prefkey may lead to delayed startup and/or silent reinstallation of the component during updates.

      1. gh said on July 27, 2016 at 12:51 am

        (replying to self because edit window expired)

        Creepy, or simply an additional potential vulnerability vector to worry about, I’m thrilled that mozilla is shipping these “system addons” (pocket, reader, flyweb) as external components rather than hiding them within the integral firefox codebase.

  13. insanelyapple said on July 26, 2016 at 9:39 am

    Would be f*n nice if they would ask first if user wants (despite of fact its in Nightly) it but it seems that being a “corporation” requires certain image to follow.

  14. Thorky said on July 26, 2016 at 7:45 am

    Well, it’s annoying to see, that Mozilla is putting more and more crap into Firefox, which users can get rid of backstage only. Firefox – the Bloatware-Browser? Yes, in the end, it will be! :(

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