Something not working?

Reload the page. If it still does not appear, confirm you are on a youtube.com/watch URL and that Chord Lens is enabled at chrome://extensions. Some other extensions rewrite the YouTube player controls and can displace the button; disabling them one at a time will find the culprit.

A small number of videos cannot be analysed: age-restricted videos, region-blocked videos, and videos where the audio cannot be retrieved. Very long videos take proportionally longer. If a specific video fails repeatedly, send me the link and I will look at that video directly.

Chord detection is a model listening to a real recording, and dense mixes, heavy distortion and quiet or ambiguous harmony all make it harder. Two things often help: turn Simplify on, which collapses extensions down to the underlying triad, and check the detected key at the top of the overlay — if the key looks wrong, the chords derived from it usually are too. Send me the link and the section that is off and it helps improve the model.

Moving the key shifts the pitch of the recording while holding the tempo still, and that is real work done on the sound as it plays. A step or two — the moves a singer actually makes — sounds clean. Push a dense, loud mix five or six semitones and you will hear it. Press the key itself to snap back to the record, and if you only need easier shapes rather than a different pitch, use the Capo setting instead: that changes the chart without touching the audio.

They cannot: they are the same control. Chord Lens sets YouTube's own playback rate, so whichever one you use, the other shows the same thing. The readout in the chart header is the tempo you are hearing rather than the multiplier — 107 BPM rather than 0.75× — and pressing it returns the song to the recorded speed.

They are stored per video, on your own computer. A different Chrome profile, or clearing your browser data, resets them — and a video you have not set anything on always starts at the recording. If a song opens at a key you did not choose, check that you are not looking at a different upload of the same song: settings follow the video ID, not the track.

Lyrics are new, and in beta. They come from the song, not from the chord model, so some songs have them and some do not — and a song without them still gets its full chart. If lyrics can be written for that song, a Generate lyrics button appears: press it once. They usually arrive in under a minute, occasionally two or three, and the overlay repaints itself when they land. If the button is not there, the words are not available for that song, and pressing anything again will not change that.

That message means the words are being written for the song right now. It is normally quick, but a slow one can take a few minutes, and the chords play on regardless — nothing is stuck. If it is still showing after five minutes, reload the page: the lyrics finish on the server either way, so they will be there next time you open the video.

Sections — intro, verse, chorus, bridge — come out of the song's first analysis and cannot be requested afterwards, so a song either has them or it does not. Most well-known songs do; obscure covers often do not. Where they exist they are the same sections the analysis found, which on a song with an unusual structure can disagree with how you would name it. This is beta, and worth mailing me about with the link.

The chart is locked to the video's own timeline and should stay in time at any playback speed. If it drifts, reload the page — a seek during the initial load can occasionally leave the overlay out of step.

Capo, key, tempo, Simplify and the diagram toggle are stored locally by the extension, per video. Clearing your browser data or using a different Chrome profile resets them.

The sheet opens in a new browser window, so a pop-up blocker can stop it. Allow pop-ups for youtube.com and click Sheet again. Once it is open, the Lead, Lyrics and Grid tabs switch between the words with chords over them, the words alone, and the numbered bar grid — and key, tempo, capo and Simplify are in that window too, so you can work from it without going back to the video.

Yes, and please do. Feature requests from people who actually play get built first.