Slow a song to 25% to learn the solo, or speed it to 200% to skim a lecture - with the pitch held steady, or dropping like a slowed record. Local playback and export; nothing uploads.
Drop an audio file here, or click to choose
MP3, WAV, AAC/M4A, OGG - stays on your device
Preserve pitch on is the practice mode: the solo stays in its key while you slow it to 50-75%, loop it in the player, and creep the speed back up as your fingers catch on. Find the song's tempo first with the BPM counter and drill against the metronome. Preserve pitch off is the tape/vinyl mode - pitch drops with speed, which is the entire "slowed + reverb" aesthetic and also how you check a mix for surprises at other keys. Trim the result to length with the audio trimmer.
Load the file, keep "Preserve pitch" on, and drag the speed slider down - the browser time-stretches the audio so a 70% speed guitar solo stays in the original key. This is the practice-tool mode: musicians learning fast passages typically work at 50-75% and step back up.
Slowing audio with pitch following (preserve pitch off), usually to 75-85% - the pitch drops with the tempo like a slowed record, giving the deep, dreamy character of the genre. Add reverb in any editor afterwards. This tool exports exactly that vinyl-style slowdown as WAV.
The two modes use different machinery. Pitch-following speed change is pure resampling, which browsers can render to a file. Pitch-preserving playback uses the media element's built-in time-stretcher, which browsers expose for playback only - there is no offline render API for it. So: practice with either mode live, export the resampled (vinyl-style) version.
Resampling (pitch-following) is essentially lossless in quality terms - it is the same math as playing a record at a different speed. Pitch-preserving stretch introduces mild artifacts that grow with distance from 100% - transient smearing and slight phasiness, usually unnoticeable between 75% and 125% and audible at the extremes. For practice they are irrelevant.
No - decoding, playback, and export all run locally in your browser. Nothing is sent anywhere, and the page works offline once loaded.