Audio Speed Changer Free Online
Slow down or speed up audio without changing the pitch, or shift the pitch (key) without changing the speed. Perfect for learning music by ear, practicing instruments along with recordings, or studying fast speech. Works with MP3, WAV, and other audio formats. Everything runs in your browser with no upload.
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- Only upload files you have the right to use. Copying or sharing other people's music, videos or recordings without permission can violate copyright law. FreeSoundTools does not store your files on a server.
When to use it
- Slow down fast guitar solos or piano passages for practice
- Speed up podcasts or lectures for faster listening
- Transpose songs to a different key for your vocal range
- Slow down language learning recordings
How to use
- Drop your audio file into the box or click to choose one.
- Adjust the speed slider to slow down or speed up (e.g., 0.5x for half speed).
- Adjust the pitch slider to shift the key up or down in semitones.
- Listen to the result and fine-tune the settings.
- Choose a format and save the modified audio.
How it works
Speed and pitch changes use time-stretching and pitch-shifting algorithms running in your browser via the Web Audio API. Slowing down without pitch change preserves the original tone, making it ideal for music practice. The processing happens entirely on your device. How to verify. Also available as a free REST API for developers and AI agents (edge-processed, zero retention).
Also available as: Speed & Pitch Changer (full controls)
FAQ
Can I change speed without changing pitch?
Yes. The speed slider changes tempo independently of pitch. A song at 0.75x plays slower but stays in the same key.
Can I change pitch without changing speed?
Yes. The pitch slider shifts the key in semitones while keeping the playback speed the same.
What is the speed range?
You can typically go from 0.25x to 4x speed, though extreme values may cause artifacts.
What formats are supported?
Input: MP3, WAV, M4A, OGG, FLAC, and other browser-supported formats. Output: MP3, WAV, FLAC.
Are my files uploaded?
No. All processing runs in your browser. Files never leave your device.
Last checked: October 10, 2026 · FreeSoundTools team