You can easily join MP4 files into one, either using free software or online tools. Here are the best ways to do it, based on your needs:
A free, open-source tool for Windows and Mac, found at mp4joiner.org . It joins files without re-encoding, preserving original quality and working quickly. Join.mp4
A popular online merger that allows you to drag-and-drop clips and add crossfade transitions. You can easily join MP4 files into one,
Another free online option that lets you add videos to a timeline, trim them, and add transitions. Important Notes for Success How To Join MP4 Files Using MP4Joiner For Free based on your needs: A free
Allows you to drag-and-drop videos, rearrange them, and add more clips, then export the final file.