Video Tools
Video Speed Changer
Speed up or slow down videos from 0.25x to 4x with audio pitch preservation.
Drop a video file or click to upload
MP4, WebM, MOV
Your videos are processed locally. Nothing is uploaded.
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About Video Speed Changer
OptiPix Video Speed Changer adjusts video playback speed from 0.25x (slow motion) to 4x (timelapse) directly in your browser. Audio speed is adjusted with pitch preservation using the atempo filter. Option to mute audio for silent speed changes. Uses FFmpeg.wasm setpts and atempo filters.
How It Works
Video: setpts={1/speed}*PTS. Audio: atempo filter (chained for speeds outside 0.5-2.0 range) to preserve pitch.
Use Cases
- •Create slow motion effects
- •Speed up tutorials
- •Create timelapse from video
- •Speed up surveillance footage
- •Slow down sports replays
Frequently Asked Questions
Speed range?
Audio pitch?
Quality?
Uploaded?
Slow motion?
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