Video Speed Changer

Change video playback speed from 0.25x (4x slower) to 4x (4x faster). Audio pitch is preserved using FFmpeg's atempo filter. Create slow-motion effects, time-lapses, or speed up long recordings.

What is it used for?

Creating slow-motion effects from normal-speed footage
Speeding up tutorials and screen recordings
Making time-lapse videos from long recordings
Adjusting pacing of content for social media

Step-by-Step Guide

Upload your video file
Adjust the speed slider (0.25x to 4x) or click a preset button
Click 'Convert to .MP4'
Preview the speed-adjusted video
Download the result

How it works

Upload a video, adjust the speed slider, and click Convert. FFmpeg adjusts video PTS (Presentation Time Stamps) and chains atempo filters to handle speeds outside the 0.5x-2x range.

Tips & Best Practices

0.5x is good for slow-motion highlights
2x is ideal for speeding up tutorials without losing comprehension
Extreme speeds (0.25x, 4x) work best for visual content without important audio

Frequently Asked Questions

Is the audio preserved when changing speed?

Yes, audio speed is adjusted to match using the atempo filter, which preserves pitch. At extreme speeds (0.25x or 4x), audio quality may degrade slightly.

Why is the audio pitch normal?

FFmpeg's atempo filter adjusts speed while preserving pitch, unlike simple resampling which would make audio higher or lower pitched.

Privacy & Security

This tool uses FFmpeg compiled to WebAssembly (WASM). The WASM binary (~25MB) is downloaded from a CDN on first use and cached by your browser. All file processing happens locally on your device - your files are never uploaded to any server. This makes it safe for sensitive, private, or confidential media files. Large files may take longer to process depending on your device's CPU and available memory.

Video Speed Changer

Settings