Browser FFmpeg recipe
Concat Videos Online with FFmpeg
Join matching clips quickly by copying streams from a concat list file.
Command
Run this FFmpeg command
ffmpeg -f concat -safe 0 -i files.txt -c copy concat.mp4When to use it
- same-format clips
- fast joins
- batch camera segments
How it works
- Upload each clip and a files.txt list that names them.
- Keep the concat input filename set to files.txt.
- Run FFmpeg and download the joined video.
Option reference
| Option | What it does |
|---|---|
-f concat | Uses FFmpeg's concat demuxer. |
-safe 0 | Allows paths listed in the concat file. |
-c copy | Copies streams without re-encoding. |
Practical notes
- The list file should contain lines like file 'clip1.mp4'.
- All clips should use compatible codecs, resolution, time base, and audio layout.
FAQ
Why did concat fail?
The concat demuxer is strict. Re-encode clips first if their stream properties differ.
Is concat faster than merge videos?
Usually yes, because stream copy avoids re-encoding.