Browser FFmpeg recipe

Change Video Speed Online with FFmpeg

Create a 2x speed video with matching faster audio.

Command

Run this FFmpeg command

ffmpeg -i input.mp4 -filter:v setpts=0.5*PTS -filter:a atempo=2.0 faster.mp4

When to use it

  • timelapse previews
  • fast tutorials
  • shorter demos

How it works

  1. Upload the video.
  2. Adjust setpts and atempo values for the speed you want.
  3. Run FFmpeg and download the speed-adjusted video.

Option reference

OptionWhat it does
setpts=0.5*PTSMakes video play at 2x speed.
atempo=2.0Makes audio play at 2x speed.

Practical notes

  • For half speed, use setpts=2.0*PTS and atempo=0.5.
  • Audio tempo values outside the supported range may need chained filters.

FAQ

How do I make a video slower?

Use a larger setpts value, such as 2.0*PTS, and a matching lower audio tempo.

Can I change video speed without audio?

Yes. Remove the audio filter and add -an if you want a silent output.