StereoToMono is a free Chrome extension developed by no9. This handy add-on allows you to monofy the currently playing video or audio source with just one click on the extension button.

With StereoToMono, you can listen to the video or audio you are currently watching in mono. It combines the content from the left speaker with the right speaker, ensuring that you hear the same sound from both speakers. This feature can be particularly useful when the stereo image in the video is unbalanced, heavily leaning to one side, or suffers from phase correlation issues. It also comes in handy if you prefer to listen to the entire audio using just one speaker.

This extension works seamlessly on both video and audio elements on pages that support this feature. Activating the extension is as simple as clicking the left mouse button on its icon. However, it is recommended to reload the page for a full sound reset after adjusting the volume with the extension.

Please note that there are a couple of known issues with StereoToMono. On some pages, it may not be possible to adjust the stereo image of the played elements due to the specific page design. Additionally, on certain pages, clicking on the extension button may cause the browser to mute the sound. This is a result of the security configuration of the page or server it is hosted on, and it cannot be detected or addressed by the extension itself.

If you find StereoToMono useful, you have the option to support the author by making a donation of any amount. Simply right-click the extension button and check the menu for more information.