Browser FFmpeg recipe

Trim Video Online with FFmpeg

Create a 30 second clip starting at the 10 second mark.

Command

Run this FFmpeg command

ffmpeg -ss 00:00:10 -i input.mp4 -t 00:00:30 -c copy trimmed.mp4

When to use it

  • quick clips
  • social snippets
  • removing intros
  • rough cuts

How it works

  1. Upload the video file.
  2. Adjust the start time after -ss and the length after -t.
  3. Run FFmpeg and download the trimmed clip.

Option reference

OptionWhat it does
-ss 00:00:10Starts reading at the 10 second mark.
-t 00:00:30Outputs 30 seconds of video.
-c copyCopies streams without re-encoding when possible.

Practical notes

  • Copy-based trimming is fast but may cut at the nearest keyframe.
  • For frame-accurate trimming, remove -c copy and re-encode.

FAQ

Why is the cut not exact?

Stream copy mode often cuts on keyframes. Re-encoding can make cuts more exact.

How do I trim the first five seconds?

Set -ss 00:00:00 and -t 00:00:05.