Video Speed Changer
Speed up or slow down any video with a single click
Drop a video file here or click to select
Video Speed Changer Features
Precise speed control for any video format
Quick preset buttons for common speeds: 0.25x, 0.5x, 1x, 1.5x, 2x, 4x and 8x.
Optional audio tempo adjustment keeps voices and music sounding natural at any speed.
Processing uses ffmpeg.wasm entirely in your browser — no video is ever uploaded.
How to Change Video Speed
Changing video speed is straightforward with our free online tool. Upload your video, select a speed multiplier, and download the processed video.
Frequently Asked Questions
Which video formats are supported?
The tool supports MP4, AVI, MOV, WebM, MKV and most other common video formats.
Processing uses ffmpeg.wasm which supports the same formats as desktop FFmpeg.
MP4 with H.264 encoding gives the best compatibility for the output file.
What is the fastest speed I can set?
The tool supports speeds from 0.1x (very slow) up to 16x (very fast).
Use the custom speed input to enter any value between these limits.
Extremely fast speeds (8x+) are useful for time-lapse style output.
Will changing speed affect audio?
With the audio option enabled, the audio tempo is adjusted to match the new speed.
This prevents the chipmunk effect at fast speeds and the deep voice effect at slow speeds.
The atempo filter works for speeds between 0.5x and 2x. Disable audio for other speeds.
Why does processing take a while?
ffmpeg.wasm runs FFmpeg entirely in your browser using WebAssembly.
Processing time depends on video length, resolution and your device's performance.
A 1-minute HD video typically takes 30-120 seconds depending on hardware.
Is there a file size limit?
There is no server-side limit since all processing is done in the browser.
Very large files (over 500MB) may exceed browser memory limits on some devices.
For best results, use files under 200MB.
Can I use this on mobile?
ffmpeg.wasm requires a modern browser with SharedArrayBuffer support.
Chrome on Android supports this. Safari on iOS may have limitations.
For mobile, use Chrome or Firefox for the best compatibility.
What happens to the audio at extreme speeds?
The atempo filter only supports 0.5x to 2.0x speed without quality loss.
For speeds outside this range, disable the audio option to mute the output.
Alternatively, the filter can be chained (e.g. 4x = two 2x passes) for higher speeds.
Is my video data private?
Completely private. Your video never leaves your device.
All processing uses ffmpeg.wasm running locally in your browser.
No data is transmitted to any server at any point.