Chrome Extension FAQ

Which sites does Music Speed Changer work on?

Music Speed Changer works on any web page that plays sound: you can slow the sound down, change its pitch and loop part of it. On sites that play music or video in a standard web player (an HTML5 audio or video element), such as YouTube, Apple Music, Pandora and Vimeo, the popup can also:

• speed the audio up to 250% as well as slow it down to 25%
• play, pause, skip back or forward 5 seconds, and jump anywhere in the track

On other sites, such as Spotify and Deezer, you can slow the music down to 25% and change its pitch, but not speed it up. The next question explains why.

What does "Out of sync" mean? Why can't I speed up some sites, and why don't the page's controls respond right away?

On sites without an audio or video element, such as Spotify or Deezer, Music Speed Changer has no choice but to capture whatever sound the tab is playing as it plays, even silence. When you slow the tempo down, the slowed audio can't keep pace with the page, so the part that hasn't been heard yet waits in a buffer. The popup then shows Out of sync. Press sync to catch up.

While audio is waiting in the buffer, the controls on the page seem to have no effect: if you pause or skip on the page, you keep hearing the audio that was captured earlier. Press Sync, the round button in the middle of the popup where the play button usually is, to clear the buffer and jump to what the page is playing now.

So that the buffer can't use up too much memory, Music Speed Changer syncs by itself once about three minutes of audio has built up.

For the same reason, these sites can't be sped up: the audio can't be played faster than the page plays it. On these sites the tempo goes from 25% to 100%.

What's the difference between Pitch and Tune?

Pitch raises or lowers the music in semitones, up to 12 semitones (an octave) either way, for example to change the key of a song. Tune makes finer changes, in hundredths of a semitone up to one semitone either way, for example to match a recording that isn't quite in tune with your instrument. Neither one changes the tempo.

How do I loop part of a song?

Press A where you want the loop to start and B where you want it to end. Music Speed Changer records the part between A and B once, then plays the recording over and over, so the end runs straight into the start without a gap. To clear the loop, press the X next to A and B.

A loop can be from half a second to one minute long. On sites with an audio or video player, the video jumps back along with the sound. On other sites, such as Spotify, A and B are the moments you press the buttons.

What does "Can't change audio on this page" mean?

Chrome doesn't let extensions work on some pages: Chrome's own pages (such as the New Tab page, Settings and other chrome:// pages), files opened from your computer, and the Chrome Web Store. Go to a web page that's playing music or video and open the popup again.

To change the speed or pitch of music files on your computer, open the ⋮ menu and choose Play local files, which opens the Music Speed Changer web app.

What does "Couldn't capture this tab's audio" mean?

Only one extension at a time can capture a tab's audio. If another extension, such as a screen recorder or another audio extension, is already capturing the tab, Music Speed Changer can't. Stop the other extension's capture on that tab, then open the Music Speed Changer popup again.

On sites with an audio or video element you can still change the tempo, because that doesn't need the tab's audio. Pitch, Tune and loops do.

What does "Stopped: this computer couldn't keep up" mean?

Music Speed Changer changes the sound as it plays, which takes some processing power. If the computer falls behind, you would hear crackling, so Music Speed Changer first switches to a larger audio buffer. The status line then mentions the larger buffer, and the sound is slightly more delayed. If that still isn't enough, it stops changing the sound rather than letting it crackle, and the tab plays normally again. Close other demanding tabs or programs, then open the popup and try again.

How do I completely stop Music Speed Changer on a tab?

Music Speed Changer does nothing on a tab until you open its popup there, and it only processes the tab's audio while a setting needs it. When the tempo, pitch and tune are back to normal and no loop is set, the tab goes back to playing through Chrome by itself after a moment.

To reset everything and stop straight away, open the ⋮ menu at the top right of the popup and choose Disconnect audio.

Get Music Speed Changer from the Chrome Web Store. For more about the extension, see the Music Speed Changer browser extension page.