Synchronized result
Video timing and audio tempo are adjusted together.
VoysumPrivate browser tool
Video Speed Changer
Create a slower or faster MP4 while keeping its audio synchronized.
No uploadNo accountFree to use
✓ Runs locally in your browser
↥Choose or drop a filevideo/mp4, .mp4 · up to 500 MB
🔒 Your media file is never uploaded to Voysum.
Private by default
Useful conversion without giving up your file.
0.5× to 2×
Create slow review clips or faster summaries.
No upload
Processing happens on your device.
Common questions
Video Speed Changer FAQ
How local browser processing works and what to expect.
Can I make a 2× video?
Yes. Select 2× and download the processed MP4.
Why is this slower than playback controls?
The tool creates a new downloadable video rather than changing player playback only.
Keep working
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