Audio Speed
Speed up a podcast, slow down a song to transcribe it, or pitch a vocal up for a meme. Pick a speed, optionally keep the pitch the same. Browser-only, no upload.
drop audio here
MP3, WAV, M4A, FLAC, OGG, AAC, video. Drop several for batch.
Pitch-preserved vs. pitch-shifted
Keep pitch uses time-stretching: speech and music sound natural just faster or slower, like a podcast player on 1.5×. The math is slightly heavier (we use FFmpeg's atempo filter), so the first run loads the codec.
Pitch + speed just plays the samples faster or slower, like a tape sped up. Vocals go chipmunk at 2× and slow drawl at 0.5×. Useful for effects, transcription of pitched material, or matching a sample to a different key.
Common use cases
- Speeding up podcasts/lectures: 1.25–1.5× with pitch preservation.
- Transcribing a fast talker: 0.75–0.9× with pitch preservation.
- Slowing a guitar solo to learn: 0.5–0.75× pitch preserved to keep the key.
- Chipmunk / demon voice effects: 1.5× or 0.5× with pitch shifted.
FAQ
What's the quality loss?
Pitch-preserve mode introduces some "phasiness" at extreme speeds (below 0.5× or above 2×). Within ±50% the result is generally clean.
Why does pitch-preserve take longer?
It runs an STFT-based time-stretch algorithm. The first run also loads the codec (~3 MB).
Does my audio upload?
No. Everything happens in your browser tab.