Play an audio file faster or slower without shifting its pitch - for podcasts, audiobooks and lectures, locally without upload.
Running locally on your device ...
Running locally on your device ...
0%
Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Listening to a podcast at double speed, an audiobook slightly slower for better comprehension, or checking a voice note in slow motion for detail: this tool changes an audio file tempo without voices suddenly sounding like a chipmunk (at faster speeds) or unnaturally deep (at slower ones).
Technically, the tool uses ffmpeg's "atempo" filter, which processes time and pitch independently - unlike simple resampling, which couples the two. The filter itself only allows a factor between 0.5x and 2x per call; for 3x, two filter passes are chained (e.g. 2x followed by 1.5x yields 3x) so that stronger tempo changes still work cleanly and pitch-preserving.
Processing runs entirely in the browser via ffmpeg.wasm - no upload, no waiting on a server. The output format is freely selectable, same as with the audio converter.
| Input formats | MP3, WAV, M4A, AAC, OGG, OPUS, FLAC |
|---|---|
| Auto-conversion | MP4 |
| Output formats | MP3, WAV, M4A |
| Batch processing | No |
| Processing | Locally in your browser (WebAssembly) |
| File upload | None |
Limitations: The factor ranges from 0.5x to 3x - stronger changes are not offered to avoid audible artifacts. This is pure tempo/pitch processing, not speech-to-text and no word smoothing; at very high speedup, speech naturally sounds rushed despite the preserved pitch. This differs from the "Change video speed" tool, which deliberately discards a video's audio track instead of processing it pitch-preservingly.
No, everything runs locally in the browser.
No. The atempo filter only adjusts tempo, pitch stays as in the original.
Beyond that, speech intelligibility suffers noticeably; the offered tiers cover the common use cases (podcast, audiobook, lecture) well.
Yes, the sibling tool "Change video speed" - there, however, the audio track is discarded, not tempo-adjusted.
Compress audio · Strip metadata · Reverse audio · Video speed