Change the speed and the pitch of a song separately, make slowed + reverb, nightcore and 8D versions, preview them and download as MP3, WAV or M4A.
Play a record slower and the music gets slow and low at the same time, because speed and pitch are tied together. This tool can pull them apart. In independent mode it time-stretches with WSOLA: it cuts the audio into frames of about 46 ms, picks the splice point where the waveform best matches the previous segment, and reassembles everything with windows that sum to 1, without rewriting any sample, so the tempo changes without turning into a chipmunk voice. Pitch is shifted by sinc-filtered resampling, in semitones (12 semitones make an octave and double the frequency) and in cents of a semitone. With the link option on, pitch follows speed as on vinyl: 0.85x lowers the pitch by 2.81 semitones and 1.3x raises it by 4.54, which is the usual slowed and nightcore recipe. There is also convolution reverb with an impulse response generated on the fly (you control size, decay and high-frequency damping), 8D audio through automatic panning, bass boost and a muffled filter. You listen to the result, compare it with the original at the same point in the song, and only then download MP3, 16-bit WAV or M4A, when the browser has an AAC encoder. The more extreme the change, the more artifacts: from 0.7x to 1.5x and up to 5 semitones the result is usually clean.
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/audio-speed-pitch-changer"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Audio Speed and Pitch Changer (Slowed + Reverb)"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
Speed (tempo) is how fast the music moves; pitch is how high or low it sounds. On a record or a basic player the two move together. Here you can change one without touching the other: 0.8x with the original pitch makes the song 25% longer without making it deeper, and +3 semitones at the same speed only makes it higher.
Audio is processed in your browser. No file is sent to a server. You are responsible for holding the rights to the music you edit.