Singing along to YouTube on a Mac
Most songs on YouTube do not have a karaoke version, and the ones that do are often the wrong key, the wrong arrangement or the wrong length. karanow takes the vocal out of the video you are already watching. This page says how, and it is honest about what a browser tab cannot give you.
Why a browser tab works at all
karanow does not talk to YouTube, to your browser, or to any application’s interface. It reads the Mac’s own output stream — the sound already on its way to your speakers — and runs a separation model on it, on your machine. From that point of view a YouTube tab is no different from Apple Music or Spotify or a video player: it is an application making sound, and the sound is what gets separated.
That is also why nothing needs to be installed in the browser, why no extension is involved, and why it works the same whichever browser is playing the video.
How it goes
Play the video. Press the button in karanow. About two seconds later — closer to three on a busy machine — the lead vocal is gone and the rest of the mix continues; you sing over that. A slider blends the original singer back in at any level, so you can keep a little of them while you are learning the tune and take them out when you are not.
Nothing is downloaded and nothing is converted. The video keeps playing where it is.
What a browser cannot tell karanow
Here is the part to know before you start. Some applications publish what they are playing — Apple Music and Spotify do, and so do players such as VLC and QuickTime Player. karanow asks them for the current track and its position, and with that it can follow along, control playback, and draw the notes to aim at from the original singing.
A browser does not answer that question. macOS offers no unified way for a third-party app to read what an arbitrary application is playing, and a browser tab has no scripting dictionary to ask, so karanow gets the sound and nothing else. With YouTube you get real-time vocal removal, and you do not get the track name, playback control from karanow’s window, or the notes to aim at. There is no workaround inside karanow for that, and we would rather you knew now than after downloading it.
This is not specific to YouTube. Any application without a scripting dictionary is the same — Bilibili and WeSing among them. After three unanswered attempts karanow stops asking that application and just keeps separating.
What you will hear
Real-time separation is not as clean as an offline pass, and video is often the harder case: live recordings with a room and a crowd in them, stacked harmonies and heavy reverb leave more traces of the vocal than a studio track does. On a clean recording the result is close to transparent. Whether that matters depends on whether you are practising or recording; for practising it stops mattering within about a verse.
Whatever the tab plays gets the same treatment, which includes an advertisement if one plays. karanow has no idea it is an advertisement; it is sound.
What karanow needs
Apple Silicon and macOS 14.2 or later. It asks for two permissions, once each: system audio recording, so it can hear the application you are playing from, and the microphone, which is used only to measure the pitch of your own singing. It produces no file — the backing track exists while it plays and is not saved, exported or uploaded.