Edit tool

Merge Videos with FFmpeg

Create FFmpeg concat commands to merge MP4 and other video files, with fast stream-copy and compatible re-encode modes.

FFmpeg.Run generates commands only. Your media files stay on your computer and are never uploaded.

Quick answer

Choose stream copy when every clip has matching codecs, resolution, frame rate, and audio. Choose re-encode mode when the files differ. Enter one file per line below, then copy both the generated files.txt content and FFmpeg command.

Command options

Presets

Input files, one per line

Output file

Merge mode

files.txt content

file 'clip-1.mp4'
file 'clip-2.mp4'
file 'clip-3.mp4'

Generated command

ffmpeg -f concat -safe 0 -i files.txt -c copy "merged.mp4"

Common uses

Join clips from the same camera
Merge MP4 files without re-encoding
Fallback to re-encoding when clips do not match

How to Merge MP4 Videos with FFmpeg (Without Re-encoding)
Merge MP4 videos with FFmpeg using fast lossless concat or compatible re-encoding. Includes files.txt, no-audio commands, checks, and common fixes.

Related command recipes

Merge MP4 Files with FFmpeg

Join multiple MP4 files using the concat demuxer.

Command notes

The concat demuxer reads file names from `files.txt` and joins them in order.

Stream copy is fast and lossless, but it works best when inputs share the same technical properties.

Re-encoding is slower, but it can fix many compatibility issues between mismatched clips.

FAQ

When can I merge without re-encoding?

Use stream copy when the clips have matching codecs, resolution, frame rate, time base, and audio layout.

Why does concat sometimes fail?

Concat fails when source files differ too much. Re-encoding is slower but more tolerant.

Do I need a files.txt list?

The concat demuxer uses a text file that lists input clips in order. This tool generates both the list content and the FFmpeg command.