Change the tempo, keep the key. Stretch any song from 25% to 200% with the pitch locked - built for learning solos, transcribing, and drilling fast passages. Nothing uploads.
Drop an audio file here, or click to choose
MP3, WAV, AAC/M4A, OGG - stays on your device
Slow the passage until every note is clean - not almost clean - then raise the tempo in steps of five to ten percent, dropping back a step whenever mistakes reappear. Speed you cannot play accurately is not speed, it is rehearsed error. Find the song's real tempo with the BPM counter, keep time against the metronome, and if you are working out the notes by ear, the pitch shifter can move the whole track into an easier key first.
Load the file and drag the tempo slider - the browser time-stretches playback in real time, so a solo at 60% speed stays in the original key. This is the standard practice workflow: start where you can play every note cleanly (often 50-75%), loop the passage, and raise the speed a few percent at a time.
Time-stretching keeps pitch fixed by cutting the audio into tiny overlapping grains and re-spacing them, which introduces mild artifacts - a slight phasiness and softened transients. Between about 75% and 125% they are hard to hear on full mixes; at 25% or 200% they are audible but the notes remain clear, which is what matters for transcription and practice.
Not from this page - browsers expose pitch-preserving stretch for live playback only, with no offline render API, so any site offering "free time-stretch downloads" is processing your file on its servers. Everything here stays on your device. If a downloadable file matters more than constant pitch, the audio speed changer exports a resampled (pitch-following) WAV.
Slow enough that you make no mistakes - speed with errors just rehearses the errors. A common progression is 60% until clean, then 70, 80, 90, 100 in separate passes, dropping back one step whenever accuracy slips. Find the song's original tempo with the BPM counter so you know what each percentage means in beats per minute.