Change Audio Speed Without Losing Control
Choose a faster or slower playback rate and decide whether pitch should stay natural.
Upload audio to retime
MP3, MP4, WAV, M4A, AAC, or FLAC · up to 200 MB
Time stretch
Retime Speech, Music, or Recordings
Change duration while controlling how voices and notes sound.
Choose audio
Add one supported track.
Set playback speed
Choose a rate and pitch-preservation behavior.
Process in VisionStory
Create and review the retimed audio.
Decision guide
Calculate the Expected Duration Before Processing
Expected duration can be estimated as source duration divided by speed. A 60-second recording at 2× would be about 30 seconds; at 0.
Calculate the Expected Duration Before Processing
This arithmetic does not guarantee the exact encoded duration because rounding, padding, and codec behavior can add small differences.
Keep the change audio speed contract honest
Make audio play faster or slower, understand the resulting duration, and choose whether pitch should remain natural. Owns tempo/playback-rate and duration change.
Keep playback rate, duration, and pitch behavior within scope
Keep playback rate, duration, and pitch behavior as the central decision and route neighboring tasks elsewhere.
Problem diagnosis
Match Speed to the Listening Task
Slower playback can help review pronunciation, interviews, or a difficult musical passage. Faster playback can shorten lectures, voice notes, or rough review.1
Apply
Match Speed to the Listening Task
Music, speech, percussion, and ambient audio respond differently, so avoid a single recommended rate.
2
Confirm
Keep the change audio speed contract honest
Owns tempo/playback-rate and duration change. It must not target semitone/key changes, cutting, transcription speed controls, or format conversion.
3
Fallback
Preserve the original when uncertain
Preserve the source whenever playback rate, duration, and pitch behavior remains unverified.
Complete in VisionStory
Finish the change audio speed result in production
Changing audio speed retimes a recording: faster playback shortens the output, while slower playback lengthens it. A pitch-preservation option can aim to keep voices and notes near their original tone instead of shifting with speed.
Keep the source ready for reselection
Actual change audio speed processing, result inspection, and download happen in VisionStory. The current handoff may require the source file to be selected again.
Approve the measured output, not an estimate
Check the properties that define a successful change audio speed result and retain the original until the destination accepts it.
Test the real receiving workflow
Confirm playback rate, duration, and pitch behavior in the intended destination before approval.
Speed control
Faster or Slower, with Intent
Tune the timing for the listening context.
Slow review
Lengthen audio for study or close listening.
Original timing
Return to the source playback rate.
Fast playback
Shorten spoken or reference material.
Frequently asked questions
Enable pitch preservation when you want voices and notes to remain closer to their original tone.
