Audio Change Speed
Change the playback speed of audio files online
How does audio speed change work?
It uses the FFmpeg atempo filter to change audio speed. Speeds outside 0.5x-2x are handled by chaining multiple atempo filters.
Is my data safe?
Yes, all processing happens locally in your browser. No data is uploaded to any server.
What audio formats are supported?
You can input most audio formats and output to MP3, WAV, AAC, OGG, FLAC, or M4A. The default output format matches your input file.
Does changing speed affect audio pitch?
No. The atempo filter changes speed without altering pitch, so the audio sounds the same except faster or slower.
What speed range is supported?
You can adjust speed from 0.25x (quarter speed) to 4x (four times faster). The slider provides fine-grained control with 0.05x steps.
Is my audio file uploaded to a server?
No. All processing happens locally in your browser using WebAssembly. Your files never leave your device.
Is this audio speed changer free?
Yes, it is completely free with no file size limits, no watermarks, and no registration required.