Audio Speed Changer
Speed up or slow down audio (0.25× to 3×) with optional pitch preservation. Browser-side.
Quick answer: Audio Speed Changer: speed up or slow down audio (0.25× to 3×) with optional pitch preservation. Browser-side. Runs entirely in your browser, free, no signup.
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Changing playback speed and changing pitch are two different operations, and this tool lets you decide which you get. Leave preserve pitch off and speeding a clip up raises the pitch (the "chipmunk" effect) because you are literally playing the waveform faster; turn it on and detune compensation holds the pitch roughly constant while only the duration changes — the setting you want for podcasts, lectures, and audiobooks.
The pitch-preservation here is a fast approximation rather than a studio-grade time-stretch, so it shines on speech and spoken-word content but can introduce faint artifacts on music, where dedicated algorithms like SoundTouch or élastique sound cleaner. For learning a fast musical passage, slowing to 0.5× is usually clear enough to transcribe by ear even with the approximation.
Common real-world uses: slow an interview to 0.75× to transcribe it accurately, speed a training video's audio to 1.5× to review it faster, or stretch a language-learning clip to hear individual phonemes. The reciprocal relationship is worth remembering — 2× halves the duration, 0.5× doubles it.
Output is WAV, because that is the only format browsers encode natively; if you need a smaller MP3 to share, pass the result through the audio converter. To reverse a clip instead of re-timing it, the audio reverser is the neighboring tool.
Frequently asked questions
- Will the pitch change with the speed?
- By default yes — speed 2× gives a higher 'chipmunk' pitch. Toggle 'preserve pitch' to apply detune compensation: the speed changes but the pitch stays close to the original.
- How accurate is the pitch preservation?
- Detune is a quick approximation — good enough for podcasts and lectures, but real time-stretching algorithms (like SoundTouch) sound better for music. We can ship that later if there's demand.
- Is the output WAV?
- Yes — browsers can only encode WAV natively. Run the result through our Audio Converter for MP3.
- Are my files uploaded?
- No — both decoding and rendering happen in your browser.
- What's the use-case for slowing audio?
- Transcribing interviews, learning a fast piece of music, breaking down speech for language learning, or making accessibility-friendly versions of fast-paced podcasts.