Free Audio Speed Changer
Speed up or slow down a track without changing its pitch, free, no sign-up, no watermark.
- File
- Run
- Result
50%–200%
Half speed to double speed.
Pitch unaffected
Key stays the same, only speed changes.
No sign-up
No account, no watermark. Up to 80MB and 15 minutes.
How it works
Simply playing a file faster or slower changes its pitch along with its speed — that's how a turntable or tape sounds higher-pitched when sped up. This tool uses Rubberband, a time-stretching engine that analyzes the waveform and reconstructs it at the new duration while holding pitch steady, rather than just playing the same data back faster or slower. That's what makes it possible to change speed and pitch completely independently of each other.
How to change audio speed
- Upload an AAC, AIFF, FLAC, M4A, MP3, OGG, or WAV file.
- Move the slider anywhere from 50% (half speed) to 200% (double speed).
- Apply the change.
- Download the result — pitch unchanged, speed and duration adjusted.
Tempo Changer vs. Pitch Shifter
| Comparison | Tempo Changer | Pitch Shifter |
|---|---|---|
| Changes | Playback speed | Musical key / pitch |
| Stays the same | Pitch and key | Tempo and duration |
| Range | 50%–200% speed | ±1 octave (12 semitones) |
One nuance worth knowing if you work in a DAW: in a MIDI or multi-track project, "tempo" (the BPM setting) and "playback speed" of an audio file are genuinely different things — changing a project's tempo doesn't necessarily change an audio clip's speed unless it's warped to follow. But for an already-rendered audio file like what this tool processes, speeding it up does proportionally raise its audible BPM, so "tempo" and "speed" end up meaning the same practical thing here.
Want the deeper explanation of why tempo and pitch are usually linked, and how much you can push a tempo change before it starts sounding artificial? Read How to Match Tempo Without Changing Pitch.
Why extreme speed changes sound different
Moderate speed changes — within roughly 10–20% of the original — tend to sound close to transparent, since the engine only has to reconstruct a small amount of extra or missing waveform data. Pushing further toward the 50% or 200% ends of the range means reconstructing much more of the signal, and that's where artifacts start showing up: sharp transients like drum hits or plucked strings can smear slightly, since a single instant in the original has to be stretched or compressed across a different span of time. It's not a flaw so much as the inherent tradeoff of asking a time-stretching algorithm to do more work — staying closer to 100% keeps results cleaner, and pushing toward the extremes trades some fidelity for the bigger change.
Common uses
- Slowing a track down to learn a fast guitar solo, drum pattern, or piano passage note-by-note
- Speeding up a lecture, audiobook, or podcast to save time
- Nudging a track's tempo to match another for a DJ mashup or beatmatch, without shifting the key
- Slowing down choreography or dance reference audio for practice
- Slowing speech down for language-learning or transcription accuracy
- Speeding through recorded meetings or interviews to skim faster
Want to know the key before you start matching tempos? Run the track through the Key & BPM Finder first.
Need to change key without affecting speed? Use the Pitch Shifter instead — same engine, applied to pitch rather than speed.
Next
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