Adjust one track at a time with automatic BPM detection, instant target-speed preview, and export.
Choose or drop an audio track to detect its BPM, preview target tempos in real time, and export.
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Automatic detection can land on half- or double-time. Before choosing a target BPM, check that the count matches the track’s actual beat.
A 10 BPM move is not equally large at every starting tempo. The relative percentage better reflects how far the timing and sound are being changed.
Preserve Pitch keeps the musical key fixed through time stretching; turning it off lets pitch and key move naturally with playback speed.
BPM sets how fast a track plays; pitch is how high it sounds. Normally, speeding a track up raises its pitch — this tool separates the two: it time-stretches the audio so the tempo changes while the key stays exactly where it was.
Drop an audio file (it never leaves your browser), let the detector read the original BPM, set the target tempo or nudge it in steps, preview both versions, then export in MP3, WAV, FLAC, OGG, or OPUS.
Keep changes within ±10% for the most transparent results — bigger jumps expose artifacts in vocals and cymbals. Turn the pitch-preserving toggle off when you want the classic vinyl-style speed-up instead.
Not always. Preview changes the original file’s playback speed in real time in the browser. Export decodes the audio, applies the tempo change, and encodes a new file in the selected format. Because the two processing paths differ, vocals, cymbals, transients, and high-frequency detail may sound different. Check the downloaded file, especially after a large change, with Preserve Pitch on, or when exporting to MP3 or OGG.
The farther the target BPM is from the original tempo, the more likely you are to hear softened transients, smeared vocals, or rough cymbals. This tool warns when the change exceeds 20%; that is a review point, not a quality guarantee. Low-bitrate or repeatedly lossy-encoded sources may also reveal more of their existing problems after processing and re-encoding.
With Preserve Pitch on, the key stays fixed, but time-stretch artifacts can grow with the tempo change and sound like unstable vocals, grainy cymbals, or softened transients. With it off, pitch-preserving time stretching is not used; pitch and key rise or fall with speed, so voices also sound deeper or brighter. Choose based on the exported file.
Processing runs on your device, so export time mainly depends on CPU performance, available memory, and track length; long tracks and lower-powered devices take longer. If export fails, close memory-heavy tabs or apps and try again with the latest browser version. If it still fails, use a computer with more available memory.
Get the latest Google ChromeUse the BPM guide for tempo ranges and key-lock decisions, the formats guide to judge source quality, and the converter when the finished edit also needs a different format.