Key Changer

Key Changer is a Chrome extension for practising along with a song in a key that suits you. Start something on YouTube, YouTube Music, Spotify Web, SoundCloud or another site, open the popup and step the pitch up or down one semitone at a time, as far as 12 either way, with a further 50 cents of fine tuning. Tempo stays the same, and the video is held back slightly so it stays in sync with the processed sound. A Keep vocals natural setting, on by default, tries to stop voices sounding cartoonish when shifted up or heavy when shifted down. The extension remembers a non-zero shift for each song and restores it when that song plays again. Audio is processed in memory on your device and is never recorded or uploaded, according to the privacy notice, and settings stay in local Chrome storage with no account. It is free during early access and published by Mikhail Eshchenko.