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Free Audio Speed Changer

Speed up or slow down audio with the pitch preserved (great for podcasts) or shifted. Export as MP3. Runs entirely in your browser, no upload.

No file size limitFiles stay privateNo login requiredFree forever

Drop files here, or click to browse

MP3, WAV, FLAC, OGG, AAC, M4A, Audio no file size limit

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Your files never leave your device. All processing happens locally in your browser.

Speed up or slow down audio — keep the natural pitch (great for podcasts and audiobooks) or shift the pitch. Runs entirely in your browser.

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Speed Up a Podcast Speed Up an Audiobook Make a Nightcore / Sped-Up Edit Make a Slowed + Reverb Edit Slow Down Audio for Transcription

How It Works

Changing audio speed can either keep the pitch natural (so a sped-up voice doesn't sound like a chipmunk) or shift it (the classic record speed-up). This does both with FFmpeg in your browser.

1
FFmpeg.wasm loads once
The WebAssembly build downloads on first use and is cached afterwards.
2
You pick a speed and pitch mode
From 0.5× to 3×, with "keep natural pitch" on or off. The file stays in your browser.
3
FFmpeg re-times the audio
Natural-pitch mode uses chained atempo filters (time-stretch); pitch-shift mode uses asetrate (speeds and pitches together).
4
Download the MP3
The result is encoded to MP3 and previewed with the built-in player.