Free · no signup · browser-local
Audio Speed Changer with Pitch Options
Change audio speed locally, choosing native pitch-changing playback or a WASM pitch-preserving stretch.
Local audio · no uploads, accounts or saved inputs
Source audio
Editable sample: 12 seconds from the 2009 U.S. inaugural address, marked public domain under U.S. law. Source and license · Steve Jobs at Stanford ↗ · Jensen Huang speeches ↗
Up to 5 mono/stereo files for joining · 512.00 MiB each / 1024.00 MiB total · 4 hours combined. Long sources load metadata and sparse preview windows; processing decodes only the selected range.
Output settings
A local tempo filter keeps pitch while changing duration. First use downloads the site-hosted encoder.
MP3 uses the local WASM encoder. Lossy re-encoding can reduce quality.
MP3 is selected by default and uses the local WASM encoder. Output supports up to 4 hours, 48 kHz and two channels within storage limits. WAV/Opus can stream; MP3, pitch preservation and crossfade require a selected range that fits the PCM working budget.
Preview and download
Prepare audio to hear the actual exported file. Changing files or settings clears the previous result.
Getting started
Choose the speed and pitch policy, preview the expected duration, then process and compare the result.
Before you use the result
Device-aware local processing: sources up to 128 MiB–1 GiB each and 2–8 hours combined depending on the reported device budget. Long supported WAV/Opus jobs stream in chunks; other formats/effect combinations use a checked PCM/WASM budget. Native codecs and temporary browser storage vary. Lossy formats may add padding.
Try an example
A 3-second clip at 1.5× is about 2 seconds; compare the two pitch policies.
How it works
Local metadata and bounded waveform sampling are loaded first. Small selections use checked PCM processing; supported long WAV/Opus operations decode and write in chunks, with two-pass peak normalization. MP3, pitch preservation and crossfade must fit their PCM/WASM budget. Large results can use local temporary browser storage. Input files are not uploaded.
Frequently asked questions
Change audio speed locally, choosing native pitch-changing playback or a WASM pitch-preserving stretch.
How do I use Audio Speed Changer with Pitch Options?
Choose the speed and pitch policy, preview the expected duration, then process and compare the result.
Does this tool upload my data?
Inputs and files are processed in your browser. Page-view analytics do not contain your tool input.
What should I check before using the result?
Device-aware local processing: sources up to 128 MiB–1 GiB each and 2–8 hours combined depending on the reported device budget. Long supported WAV/Opus jobs stream in chunks; other formats/effect combinations use a checked PCM/WASM budget. Native codecs and temporary browser storage vary. Lossy formats may add padding.