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Re-encodes every frame, which is slow on a phone. On a phone, stick to clips under about 1 minute (roughly 100 MB); use a computer for longer or 4K videos.
Re-encodes every frame, which is slow on a phone. On a phone, stick to clips under about 1 minute (roughly 100 MB); use a computer for longer or 4K videos.
Change video playback speed from 0.25x to 4x, with automatic pitch-preserving audio — all processed privately in your browser.
Drag and drop a video here, or click to browse
MP4, WebM, or MOV — up to 500MB
Upload a video to change its speed
This free tool speeds up or slows down any video, from 0.25x slow motion to 4x fast forward, while keeping voices at their natural pitch. Everything runs locally in your browser via WebAssembly — nothing is uploaded.
Is this video speed changer really free?
Yes. There's no signup, no watermark, and no limit on how many videos you process — everything runs in your browser.
Does my video get uploaded to a server?
No. Speed changes happen entirely locally using FFmpeg compiled to WebAssembly. Your file never leaves your device.
What video formats can I upload?
MP4, WebM, and MOV (QuickTime) are supported, up to 500MB per file.
Does changing speed make voices sound chipmunky?
No. The tool changes how fast the audio plays without changing its pitch, so voices sound natural whether you slow a video down to 0.25x or speed it up to 4x — no chipmunk voices and no slow-motion growl.
Can I remove the audio instead of speeding it up?
Yes. Turn on the "Remove audio" toggle to export a silent video at your chosen speed, skipping audio processing entirely.
Will the sound stay in sync with the picture?
Yes. The picture and the sound are sped up or slowed down by exactly the same amount, so speech still lines up with lip movements. Extreme speeds such as 0.25x and 4x are applied to the audio in two smaller steps behind the scenes to keep it clean — you don't need to do anything.
Your video is processed entirely in your browser using WebAssembly. It is never uploaded, stored, or seen by our servers.