Chrome: timeouts/interval suspended in background tabs?

There is a solution to use Web Workers, because they run in separate process and are not slowed down

I've written a tiny script that can be used without changes to your code - it simply overrides functions setTimeout, clearTimeout, setInterval, clearInterval

Just include it before all your code

http://github.com/turuslan/HackTimer

I recently asked about this and it is behaviour by design. When a tab is inactive, only at a maximum of once per second the function is called. Here is the code change.

Perhaps this will help: How can I make setInterval also work when a tab is inactive in Chrome?

TL;DR: use Web Workers.

I have released worker-interval npm package which setInterval and clearInterval implementation with using Web-Workers to keep up and running on inactive tabs for Chrome, Firefox and IE.

Most of the modern browsers (Chrome, Firefox and IE), intervals (window timers) are clamped to fire no more often than once per second in inactive tabs.

You can find more information on

https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setInterval

https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers#Timeouts_and_intervals

Playing an empty sound forces the browser to retain the performance. I discovered it after reading this comment: How to make JavaScript run at normal speed in Chrome even when tab is not active?

With the source of that comment found here:

The Chromium insider also clarified that aggressive throttling will be automatically disabled for all background tabs “playing audio” as well as for any page where an “active websocket connection is present.”

I need unlimited performance on-demand for a browser game that uses WebSockets, so I know from experience that using WebSockets doesn't ensure unlimited performance, but from tests, playing an audio file seems to ensure it

Here's two empty audio loops I created for this purpose, you can use them freely, commercially: http://adventure.land/sounds/loops/empty_loop_for_js_performance.ogg http://adventure.land/sounds/loops/empty_loop_for_js_performance.wav

(They include -58db noise, -60db doesn't work)

I play them, on user-demand, with Howler.js: https://github.com/goldfire/howler.js

function performance_trick()
{
    if(sounds.empty) return sounds.empty.play();
    sounds.empty = new Howl({
        src: ['/sounds/loops/empty_loop_for_js_performance.ogg','/sounds/loops/empty_loop_for_js_performance.wav'],
        volume:0.5,
        autoplay: true, loop: true,
    });
}

It's sad that there is no built-in method to turn full JavaScript performance on/off by default, yet, crypto miners can hijack all your computing threads using Web Workers without any prompt.