Always active Window - Always Visible is a free Chrome extension developed by brian.girko. This extension protects against web pages tracking the activity state of the page by spoofing the visibility state event. By injecting a small script into every webpage, it pretends that the tab is always in the active state, preventing websites from offering limited services only when the tab is active.

One of the main benefits of installing this extension is that it ensures immediate playback of resources on webpages that check the visibility state before loading. Even if the page is opened in the background, the player will start immediately as if the page is loaded on an active tab.

Always active Window - Always Visible supports various trackings, including document.mozHidden on Firefox and document.webkitHidden on Chromium browsers. It also supports events like visibilitychange, webkitvisibilitychange, mozvisibilitychange, blur, and mouseleave, making it versatile in preventing tracking and ensuring a seamless browsing experience.

Please note that currently, there is no exception list, so the extension injects the script on all HTTP and local HTML pages. If you need to bypass the default always active behavior, you can disable the extension from the options page. Additionally, on Chromium browsers, you can limit the script injection to specific hostnames using the right-click context menu item called "This Can Read and Change Site Data" over the browser action button.