1626121 - Slack video conferencing is not supported in Firefox

Status: RESOLVED FIXED

(Web Compatibility :: Site Reports, defect, P1)

Description

[Marco Castelluccio [:marco]]

STR:

1. Open Slack
2. Open a direct conversation with someone
3. Press on the telephone icon on the top-right part of the screen

Slackbot will send you a message saying Unfortunately, Slack calls aren't available in this browser. We recommend downloading the Slack desktop app, or you can switch to Chrome..

Comment 1

[Karl Dubost💡 :karlcow]

Marco, do you have steps to reproduce?

Comment 2

[Marco Castelluccio [:marco]]

I've updated the first comment with steps to reproduce. Funny wording from Slack BTW.

Comment 3

[Adam Stevenson [:adamopenweb]]

We have some history of this here:
https://github.com/webcompat/web-bugs/issues/12975

Comment 4

[Nils Ohlmeier [:drno]]

To summarize my current understanding: Slack's video conferencing service only support Chrome's non-standard Plan B format for WebRTC calls. And our attempts to talk to Slack about changing that were kindly rejected (we met with them shortly after they had launched the calling feature). And my repeated questions in public events about adding Firefox support were also turned down.

Comment 5

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Comment 6

[Mike Taylor [:miketaylr]]

I'm not sure if this should be a WONTFIX, or we just leave it open. But like Nils has said, Slack has not shown any interest in fixing this.

Comment 7

[Gustavo Homem]

Is it absolutely certain that it is Slack misbehaving? I think it is a disgrace that they only support the new IE. However with Jitsi there was some controversy in regards to Firefox missing some implementation of the standard that developers were expecting ( I think this is finally fixed ).

By the way, Zoom and Skype are other cases of Chrome-only horror. Whereby OTOH was amazingly well with Firefox.

Comment 8

[Mike Taylor [:miketaylr]]

Slack's video conferencing service only support Chrome's non-standard Plan B format for WebRTC calls

It's not a question of misbehaving or not, it's a question of not supporting standard ("unified plan") WebRTC.

Comment 9

[Gustavo Homem]

(In reply to Mike Taylor [:miketaylr] from comment #8)

Slack's video conferencing service only support Chrome's non-standard Plan B format for WebRTC calls

It's not a question of misbehaving or not, it's a question of not supporting standard ("unified plan") WebRTC.

That is what I meant by misbehaving - not following the standard.

Comment 10

[Nils Ohlmeier [:drno]]

(In reply to Gustavo Homem from comment #7)

Is it absolutely certain that it is Slack misbehaving? I think it is a disgrace that they only support the new IE. However with Jitsi there was some controversy in regards to Firefox missing some implementation of the standard that developers were expecting ( I think this is finally fixed ).

By the way, Zoom and Skype are other cases of Chrome-only horror. Whereby OTOH was amazingly well with Firefox.

All of these (at some point) not working with Firefox basically come down to two things:

1. They all started with implementing the video calling the Chrome way, which never got standardized, and Firefox supporting the official standardized way from early on.
2. The differentiator between the service which now work with Firefox and the ones which still don't work is basically their willingness to work with us on adding support for Firefox by implementing support for the standardized way (which Chrome meanwhile supports now as well).

Comment 11

[Andrei Petcu]

If you are using Slack at work please report this issue on their support page. Maybe enough of us will help them make the switch https://uipath-product.slack.com/help/requests

Comment 12

[Gustavo Homem]

(In reply to Nils Ohlmeier [:drno] from comment #10)

(In reply to Gustavo Homem from comment #7)

Is it absolutely certain that it is Slack misbehaving? I think it is a disgrace that they only support the new IE. However with Jitsi there was some controversy in regards to Firefox missing some implementation of the standard that developers were expecting ( I think this is finally fixed ).

By the way, Zoom and Skype are other cases of Chrome-only horror. Whereby OTOH was amazingly well with Firefox.

All of these (at some point) not working with Firefox basically come down to two things:

1. They all started with implementing the video calling the Chrome way, which never got standardized, and Firefox supporting the official standardized way from early on.
2. The differentiator between the service which now work with Firefox and the ones which still don't work is basically their willingness to work with us on adding support for Firefox by implementing support for the standardized way (which Chrome meanwhile supports now as well).

Thank you. That clarifies it.

Comment 13

[Oana Arbuzov [:oanaarbuzov]]

I can still reproduce the issue.
https://prnt.sc/xdmjwo

Tested with:
Browser / Version: Firefox Nightly 86.0a1 (2021-01-20)
Operating System: Windows 10 Pro

Comment 14

[wbob]

as no one has mentioned user-agent spoofing (addon) yet, coming from the "huddle" feature in bug#1727100 - by spoofing Chrome in ff92 you can initiate a call and the audio works bi-directional (though on second try, could've been permissions) - the video in my case worked only for the incoming video stream (Linux/Wayland/PipeWire).

As audio is the most important element, this is something gained - downside: it will skew their user-agent stats.

Comment 15

[Chris Lane]

(In reply to wbob from comment #14)

as no one has mentioned user-agent spoofing (addon) yet, coming from the "huddle" feature in bug#1727100 - by spoofing Chrome in ff92 you can initiate a call and the audio works bi-directional (though on second try, could've been permissions) - the video in my case worked only for the incoming video stream (Linux/Wayland/PipeWire).

As audio is the most important element, this is something gained - downside: it will skew their user-agent stats.

I use the User-Agent Switcher addon to always set my user-agent to Windows/Chrome 87 and it works great.

I join and occasionally initiate Slack video calls every week day on Firefox (Linux/Wayland/PipeWire) and both sending and receiving video/audio works flawlessly. The only issue that I've come across is that it takes longer to start a call from Firefox than it does on Chromium, joining calls is fine.

Comment 16

[Chris Lane]

In addition to the above, screen-share works too.

Comment 17

[acheronfail]

So I can use huddles for audio, but when I host screensharing it doesn't work - the console shows this error which I think may be the cause:

TypeError: RTCPeerConnection.getStats: Argument 1 does not implement interface MediaStreamTrack.

Other than that, after swapping the User-Agent the audio works perfectly, I can see others' screens when they share, it just doesn't seem to work when I share myself.

Comment 18

[acheronfail]

That may not be the right error actually - it seems to fire periodically when I'm in a audio call regardless of the sharing state or not...

Comment 19

[acheronfail]

Oh, sorry for the noise - seems that screensharing does work in Firefox! I've set the user agent to

Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.7113.93 Safari/537.36

I didn't have to do anything more to get it to work (my co-workers who joined the Huddle had technical connectivity issues on their end and that was the original issue).

Comment 20

[Jan Alexander Steffens [:heftig]]

I can now use Calls and Huddles in Firefox. No need to spoof the user-agent.

Comment 21

[Karl Dubost💡 :karlcow]

This was fixed by Bug 1727100 and Bug 1720142
The webcompat team created a site intervention so it would work for everyone.
https://github.com/mozilla-extensions/webcompat-addon/pull/245/commits/44ce3f4507f2c25b7817697db31afce246ff7621

Firefox sends a Chrome UA to Slack app.
Slack has been notified.

Comment 22

[Dustin Oprea]

I'm still having issues opening a call in Firefox 98, but it seems like the above should be working as of 95. When I click on the button, which is clickable, nothing happens. Works fine in Chrome (well, Brave, actually). No obvious in-UI messages or errors. Same issue or different issue?

Comment 23

[Chris Lane]

I'm still having issues opening a call in Firefox 98, but it seems like the above should be working as of 95. When I click on the button, which is clickable, nothing happens. Works fine in Chrome (well, Brave, actually). No obvious in-UI messages or errors. Same issue or different issue?

Same issue.

The intervention was removed in this commit: https://github.com/mozilla-extensions/webcompat-addon/commit/61d167105fa195792c82c23125f1d6d23f6e6c36

The commit is connected to this bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1745313

The bug states that Slack support Firefox for huddles, unfortunately huddles aren't particularly useful if you want to screen-share.
I should also note that Slack only supports huddles for Windows and mac OS. Any Firefox users on Linux still have to use an extension to manually set the user-agent.(In reply to Dustin Oprea from comment #22)

Comment 24

[Vitaly Zdanevich]

Firefox 102: "Unfortunately, Slack calls aren't available in this browser. We recommend downloading the Slack desktop app, or you can switch to Chrome."

Comment 25

[juraj.masiar]

I've tried to make a Slack call today using my Firefox 105 (right click / Call xxx). I couldn't.
A friend called me, but the button to join the call didn't do anything.
And then we used the "huddle" feature which worked for sound, but when he shared the screen and I clicked the small small thumbnail preview to make it a popup, the image in the popup didn't update at all.

Then I reopened it in Chrome and it all worked, even the popup in "huddle".
And the friend told me I'm the only person he knows that uses Firefox. That was sad thing to hear.
I've send a report to Slack, but I'm not sure that's helpful enough :(.

If there is no easy way to fix it on Firefox side, and we know we only need to change user agent, maybe implement some "Helper" addon that would show you notification on Slack saying - "Hey, did you know Slack is stupid and will not allow you to call? Click here to apply 'Chrome-like' cloak to fix it". And I'm sure the same fix could be used on many other pages. It could be maybe community driven. Instead of driving users out of Firefox :)