Tempo Changer — Faster or Slower, Same Pitch
Speed up or slow down music, pitch stays true.
Runs 100% in your browser — nothing is ever uploaded.
What is Tempo Changer?
Change the tempo of any track from 50% to 200% without altering the pitch. Free, private and 100% in your browser — WAV export. Upload an audio file, tune the settings, preview the result and download it as a WAV file. No installation, no account and no upload: the whole process happens client-side in your browser, which keeps your data 100% private.
How to use Tempo Changer
- Open Tempo Changer — it supports MP3, WAV, OGG, M4A and FLAC.
- Upload your audio file; it is decoded locally in your browser.
- Tune the settings, then click Process to render the result.
- Preview the output and download it as a WAV file.
Frequently asked questions
How much can I change tempo before it sounds wrong?
Roughly 0.9× to 1.15× is transparent on most music. Down to about 0.75× or up to 1.3× is usable but audible, typically as a slight flutter on sustained notes. The 50% and 200% extremes work for speech and for creative effect, but not for anything you want to sound untouched — time-stretching reconstructs the signal, and the further you stretch, the more reconstruction shows.
Does changing tempo affect the pitch?
No, that is the point of this tool: a track sped up to 1.2× stays in the same key. If you want pitch to rise with speed — the classic tape or vinyl behaviour — that is a playback-rate change, not a tempo change, and the Slowed + Reverb tool does it. Keeping them separate is what lets you speed up a podcast without everyone sounding like a cartoon.
What speed should I use for podcasts and audiobooks?
1.25× to 1.5× is the range most listeners adapt to within a minute or two while keeping full comprehension. Past about 1.8× the gaps between words shrink faster than the words themselves, so you lose the pauses your brain uses to parse sentences. Dense technical material is best kept below 1.4×.
Are my audio files uploaded?
Never. Your file is decoded and processed with the Web Audio API directly in your browser. It never touches a server — processing even works offline.
What formats can I upload and download?
Upload anything your browser can play: MP3, WAV, OGG, M4A/AAC and FLAC in most browsers. The processed result downloads as a high-quality WAV file.
Is it really free? Any length limit?
Completely free with no watermark. There is no hard length limit — a typical 3-5 minute song processes in seconds; very long files just need more memory.