Try setting media.block-autoplay-until-in-foreground to false in about:config. I think Beta and Nightly have this pref enabled by default now. Certainly helps a lot for me.

Edit: Also, I see that you are using v24 of Flash. If you choose to continue using Flash, please be sure to ALWAYS keep it updated. Flash is very vulnerable and security flaws are rampant in past versions.

Moses said

Try setting media.block-autoplay-until-in-foreground to false in about:config. I think Beta and Nightly have this pref enabled by default now. Certainly helps a lot for me. Edit: Also, I see that you are using v24 of Flash. If you choose to continue using Flash, please be sure to ALWAYS keep it updated. Flash is very vulnerable and security flaws are rampant in past versions.

It was already set to false. I tried toggling it but both settings did not change anything.

Question: Does any part of the Twitch webpage load in the background?

Question: Do other websites load in the background like YouTube?

Yes, the entirety of the page loads but the stream is just a black screen. It also doesn't go to other streams if the one i went to is hosting someone else.

Yes, Youtube loads in the background and starts to play correctly.Fiz said

Question: Does any part of the Twitch webpage load in the background? Question: Do other websites load in the background like YouTube?

Yes, the entirety of the page loads but the stream is just a black screen. It also doesn't go to other streams if the one i went to is hosting someone else.

Yes, Youtube loads in the background and starts to play correctly.

Is the player into view when the page loads?

YouTube only continues playing a playlist or proceed the the next item if I leave the player into view. If I scroll down the page to look at some comments then I need to scroll to the top to make the next video start. This happens regardless whether the YouTube page is selected or not. i.e. if I switch to another tab and forget to scroll the player into view then loading the next video fails.

The likely culprit is the JavaScript Event Listener viewport code in Twitch's https://player.twitch.tv/js/player.js checking to see if you're watching. They're probably doing this to save on bandwidth, and/or so you watch the ads. Looks like they're doing it on purpose. It behaves the same way in other browsers.

Specifically: "canUseViewport:n&&!!window.screen,isInWorker:"

I can't think of an easy way to change this unless you wrote an add-on that modified their JavaScript.

Any chance in creating a setting that allows all tabs to act like they are active tab to avoid issues such as this?

The tabs are behaving as active tabs when you set media.block-autoplay-until-in-foreground to false (test it with YouTube). Content loads as expected. Twitch has purposely written code on their website to prevent the functionality you desire. This is apparent, as the "issue" is prevalent across browsers. They obviously prefer people not simultaneously launch a bunch of streams unless they intend to watch them. A third party add-on would be required, to re-write or remove their JavaScript code, for the functionality you desire.

Source: Chrome by default will not allow a streaming video to play in a background tab until you view it, however there is a setting under chrome://flags/ called "Gesture requirement for media playback" which will allow background tabs to playback video when disabled(like with YouTube). This doesn't work for Twitch, as Twitch has additional code to prevent it.

Suggestion: Use Shift+Left Click and open the link in new window then hit Alt+Tab to go back to your other window.