Audio Speed Changer

Speed Up or Slow Down Any Audio — In Your Browser

Drop in an MP3, M4A, AAC, WAV, OGG, or FLAC file, drag the speed slider anywhere from 0.5× to 2×, and download the result as a lossless 16-bit WAV. You hear a live preview as you drag, so you can settle on the exact pace before rendering a single byte.

Everything happens locally with the Web Audio API — your file is decoded, resampled through an offline audio context, and re-encoded to WAV inside the page. Nothing is uploaded, there's no sign-up, and because there's no engine to fetch, the tool keeps working offline once the page has loaded.

One honest caveat: this is a tape-style speed change, so speed and pitch move together. A faster clip sounds higher and a slower clip sounds lower, exactly like spinning a record or tape at the wrong speed. It is not pitch-preserving time-stretch, so it will not hold a voice at its original tone while it speeds up — the tool shows you the approximate semitone shift for whatever speed you pick.

• Nightcore and slowed edits: push a track to 1.5× for a bright, sped-up feel or drop it to 0.75× for a slowed-and-reverb vibe.
• Faster listening: speed a lecture, sermon, or audiobook to 1.25×–2× to get through it in less time.
• Slow down for transcription: take a fast interview or dictation to 0.5× so you can catch every word.
• Learn a part by ear: slow a solo, riff, or vocal run down to hear exactly what's being played.
• Sound design: pitch a sound effect up or down by changing its speed for a quick creative variation.
• Fix a wrong-speed recording: nudge a clip that came off a device running slightly fast or slow back toward normal.

Privacy: this tool runs entirely in your browser. Your audio is decoded, sped up, and encoded on your own device using the Web Audio API — the file is never uploaded to a server, and the temporary buffers are released as soon as the WAV is ready.