Tools like LosslessCut or Avidemux can merge MP4s instantly without re-encoding, as long as they have the same resolution and frame rate.

If you're uploading this to a professional platform (like a webinar or work portal), ensure there are in the filename (e.g., keep it as g61029.mp4 rather than g 610 29!.mp4 ) to avoid upload errors.

On Windows, you can use the Microsoft Photos or Clipchamp app. Just drag your clips into the timeline and hit export. 2. Editing & Enhancing

mp4 . Whether you need to join it with other clips, edit it, or just figure out why it won't open, 1. Combining with Other Clips