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Audio Speed Changer

Your audio never leaves your device
Drop an audio file here or click to browse MP3, WAV, FLAC, OGG, AAC, M4A, WMA, WebM

How to Change Audio Speed Online

  1. 1

    Upload your audio file

    Drop your audio file onto the upload area or click to browse. MP3, WAV, FLAC, OGG, AAC, and M4A are supported.

  2. 2

    Set the speed

    Use the slider for precise control or tap a preset (0.5×, 1.5×, 2×, etc.). The estimated output duration updates in real time. Toggle "Preserve Pitch" based on whether you want natural-sounding speech or a pitch-shifted effect.

  3. 3

    Download the result

    Click "Change Speed" and download your processed file when complete. Everything runs in your browser — no upload, no waiting for a server.

Speed vs Pitch: What's the Difference?

Preserve Pitch (Recommended)

Speed changes, pitch stays the same. A lecture at 1.5× sounds faster but the speaker's voice stays natural — no chipmunk effect. Uses ffmpeg's atempo filter for time-stretching.

Best for: Podcasts, lectures, audiobooks, meetings, language learning.

Change Pitch with Speed

Speed and pitch change together. At 2× the voice becomes higher pitched; at 0.5× it becomes deeper — like a vinyl record played at the wrong speed. Uses asetrate for authentic pitch shifting.

Best for: Creative effects, music experiments, vintage audio aesthetics.

Frequently Asked Questions

Is my audio uploaded to a server?
No. All processing happens entirely in your browser using WebAssembly. Your audio files never leave your device.
What speed range is supported?
You can change audio speed from 0.25× (quarter speed, 4× slower) to 4× (four times normal speed). The slider moves in 0.05× increments for fine control, and common presets are available for quick selection.
What does "Preserve Pitch" do?
With Preserve Pitch on (the default), the pitch of the audio stays the same regardless of speed — speech sounds natural at 1.5× or 2× speed. With Preserve Pitch off, the pitch changes with the speed, like playing a vinyl record at the wrong RPM. This gives a robotic or chipmunk-like effect and is mainly used for creative purposes.
Will speed changing affect audio quality?
Pitch-preserving speed change (atempo) involves some processing but quality loss is minimal at normal speed ranges (0.5× – 2×). At extreme values (0.25× or 4×) artefacts may become noticeable. The output file keeps the same format as the input.