Audio Speed Changer
Speed up or slow down an audio file from 0.25× to 4×, with an option to keep the original pitch, then download it as WAV.
Drag & drop an audio file here, or click to browse
MP3, WAV, M4A, OGG, FLAC or WebM. No uploads — your file stays on your device.
Below 1× is slower, above 1× is faster. Range: 0.25× to 4×.
Result
How it works
Drop in an audio file and this tool decodes it with the Web Audio API right inside the page — nothing is uploaded, so podcasts, lecture recordings, interviews and voice memos never leave your device. Drag the slider (or tap a preset) to speed the audio up or slow it down anywhere between 0.25× and 4×, and the new version is rendered instantly for you to play back.
With Keep the original pitch ticked, the audio is time-stretched with an overlap-add algorithm: a 2× speed-up plays twice as fast but voices still sound like themselves. Untick it and the file is resampled the old-fashioned way, so faster also means higher-pitched — handy for chipmunk effects or for matching a sample to a track. The result is saved as an uncompressed 16-bit WAV, which every editor, player and phone can open.
Frequently asked questions
How do I change the speed of an audio file?
Drop an MP3, WAV, M4A, OGG, FLAC or WebM file onto the page, then drag the speed slider or tap a preset such as 0.75× or 1.5×. The new version is rendered straight away in a player so you can listen before saving, and the download button gives you a 16-bit WAV that any editor, player or phone can open. Anything from a quarter speed (0.25×) to four times as fast (4×) works, and you can keep nudging the slider until it sounds right.
Can I slow audio down without making it sound deeper?
Yes, leave "Keep the original pitch" ticked. The tool then time-stretches the audio with an overlap-add algorithm that repeats or skips tiny overlapping grains, so a lecture at 0.75× still sounds like the same voice, just slower. Untick the box and the file is resampled instead, which changes speed and pitch together: 2× is exactly twelve semitones higher, 0.5× twelve semitones lower. The page tells you the semitone shift whenever pitch lock is off.
Is my audio uploaded to a server?
No. The file is decoded and re-rendered with the Web Audio API inside your browser tab, so it never leaves your device. There is no upload, no account, no ads and no shareable link that could leak an interview or a private voice memo by accident. It also means there is no file-size cap beyond your device's memory, and the tool keeps working offline once the page has loaded.