Combine multiple video clips into one MP4, normalized for compatibility
What is the Video Merger?
The video merger works like this: it combines multiple video clips into one MP4, normalizing each to compatible encoding first so different resolutions, codecs and framerates merge cleanly. Everything happens on your device - the input never leaves your tab unless the tool clearly states it performs a server-side lookup.
How to use the Video Merger
Add your clips in the order you want them joined.
Reorder with the arrows if needed.
Press Merge - each clip is normalized then concatenated (progress shown).
Download the merged MP4.
Features
Powered by in-browser FFmpeg (WebAssembly)
Your files never upload anywhere
Progress shown while processing runs
Common mistakes to avoid
Choosing bitrates below the platform minimum
Re-encoding already-compressed files repeatedly
Examples
Input
Result
A 720p intro + a 1080p body clip
One continuous MP4 that plays everywhere
Best used for
Getting a reliable answer for video merger without installing an app
One-off tasks done in under a minute from any device
Checking results before committing them to something important
Working on a phone where desktop software is unavailable
Privacy
Audio and video processing runs on your device with WebAssembly FFmpeg; your files are never uploaded.
Frequently asked questions
Why normalize instead of joining directly?
The concat demuxer requires identical codecs and dimensions; mixed clips would fail or produce broken playback otherwise.
How long can clips be?
Total input under ~10 minutes processes comfortably in the browser; longer projects are better served by desktop editors.
How are mismatched clips handled?
Each clip is normalised to compatible encoding first - different resolutions, codecs and framerates all merge cleanly instead of producing a broken file.
Which output does the merge produce?
A single MP4 in the order shown, playable everywhere MP4 is - the universal safe container for merged footage.
Related tools
Video Trimmer - Cut video online, trim MP4, MKV, MOV by start and end time
Video Converter - Convert MKV to MP4, MOV to MP4, AVI to MP4, WebM to MP4, MP4 to GIF online free