This browser extension displays a context menu item Open in mpv for links. When clicked it will pass the URL of the link to mpv (which must be PATH).

If you have yt-dlp installed and in PATH, then mpv will try to use it to resolve URLs it cannot handle. This means you can right-click on any YouTube video page or link, choose Open in mpv and view the video with mpv.

First, install the extension. Quit your browser.

There are many ways to perform the next step. Below is the most basic, assuming you have Pip installed.

Gentoo users can simply install media-video/open-in-mpv from my overlay.

pip install --user open-in-mpv
open-in-mpv-install --user --force

The above commands will install the native host JSON file to supported Chromium-based browsers whose paths are known for your OS. --force is used on first install to create the necessary paths if they do not exist.

See open-in-mpv-install --help for more options. Linux users can pass the --system option to install the native host part of the extension system-wide.

open-in-mpv-uninstall
pip remove --user open-in-mpv

Uninstall the extension from your browser.

Linux: mpv is launched with --gpu-api=opengl because with Vulkan it starts but fails to open a window.

At this time, Windows is not supported by the open-in-mpv Python script. It may work, but it is not supported.