Video Speed Changer
Change video speed from 0.25× to 4×. Audio pitch is corrected automatically — no chipmunk effect.
Good for speeding up a long screen recording walkthrough to share as a quick demo.
Drop files here
or click to browse · paste from clipboard
Accepts .MP4, .MOV, .WEBM, .AVI, .MKV, .WMV · Up to 1,000 files
How it works
Drop your files
Drag and drop, click to browse, or paste from clipboard. Up to 1,000 files at once.
Choose settings
Adjust quality, format, and other options to match your needs.
Click Convert
Everything runs in your browser via WebAssembly. Video Speed Changer happens locally — no server involved.
Download
Download files individually or grab all at once as a ZIP.
Frequently asked questions
No. The tool uses ffmpeg's atempo filter, which adjusts playback speed without changing pitch. At 2× speed the audio sounds the same pitch as the original, just faster.
Changing speed requires re-encoding every frame of the video. This is CPU-intensive and takes proportionally longer than the original duration at slower speeds. A 5-minute 1080p video at 0.5× speed (now 10 minutes of output) may take 5–10 minutes to process.
Not currently — use one of the preset values. Slow motion (0.25×, 0.5×) and fast forward (2×, 4×) cover the most common use cases.
The atempo filter for audio pitch correction only works in the 0.5×–2× range per pass. Speeds of 0.25× and 4× require chaining two atempo filters — this works correctly in this tool, but very extreme slow-motion (0.25×) may produce choppy results if the source video has a low frame rate (under 24 fps). Also, very large files at slow speeds produce correspondingly large output files.
Yes. All files get the same speed applied. Results are packaged in a single ZIP.