Change audio speed from 0.25× to 4×, hear changes live and export a new WAV. Speed and pitch change together.
No file selected.
Up to 128 MiB per file; decoded audio up to 256 MiB (about 23 min mono / 11½ min stereo). Formats depend on your browser's decoder. Working audio and WAV exports use 48 kHz.
Choose audio to begin. Nothing plays automatically.
No audio loaded
Your waveform will appear here.
Load audio to choose a section.
Click the waveform to seek the source; use Play/Pause, exact time or jump controls. Speed changes apply live while playing. Faster playback raises pitch, slower playback lowers it. The source ruler always shows original source time.
Playback stopped.
Change the speed while playing to hear it immediately. Uncheck to compare original speed; exports always use the chosen speed.
The original file stays unchanged.
Input up to 128 MiB; source and rendered float audio each have a 256 MiB limit. Slowdowns may exceed the output budget even when live preview works. Fine speeds use browser floating-point precision; exported duration rounds up to a whole sample. Resampling quality depends on your browser.
Create a WAV to preview the actual adjusted file.
48 kHz · 16-bit PCM WAV · original channel count. Browser decoding/rendering may resample input; no pitch preservation, normalization or beat alignment is added. Resampling can change peaks; out-of-range samples are clipped and counted. Tags/artwork are omitted. Changing settings clears old exports. Native rendering stops logically and discards late results; a new export waits for the previous native render to settle.
Your audio is never uploaded to any server. All decoding, playback, rendering and WAV encoding happen locally in your browser with self-hosted code. Your original file stays unchanged.
No. Speed and pitch change together: 2× plays twice as fast and raises pitch by one octave; 0.5× doubles duration and lowers pitch by one octave. Independent tempo and pitch processing are separate workflows.
Source seeking uses original audio seconds. The actual exported player uses adjusted seconds. Browser floating-point speed precision and rounding up to a whole output sample can slightly change the exact duration.
One file up to 128 MiB, mono or stereo, decoded at 48 kHz within a 256 MiB float-audio budget. Rendered output has the same float budget; slowdowns can exceed it even when live preview works. Formats depend on your browser and memory may impose lower limits. Export is 48 kHz 16-bit PCM WAV with the original channel count; tags and artwork are omitted.
Yes. Obsolete results are discarded and the encoding worker is terminated. Native browser rendering cannot be forcibly terminated; new exports wait for the previous render to settle. Changing speed invalidates old downloads. Original-speed comparison affects monitoring only.
No normalization is added. Native resampling quality depends on the browser and can change peaks. Samples beyond the WAV range are clipped and counted; the actual encoded WAV is available to audition before download.
