Video Merger — Two Clips In, One MP4 Out

Joining a 47-second and a 72-second clip into one

The Video Merger takes two clips and writes them into a single continuous MP4, entirely on your device. I use it for screen captures: an intro take running 47 seconds plus the main demo at 72 seconds go in as Clip A and Clip B, and the output plays 119 seconds straight — 1 minute 59 seconds — no gap, no fade, no watermark. Because both takes came off the same recorder, the codecs match and the tool joins them by stream copy, which takes seconds and loses zero quality.

The one rule is matching inputs. Two clips from the same phone or the same screen recorder sail through; a 1080p clip followed by a 720p one, or MP4 meeting MOV, can produce a file that plays fine in one app and stutters in another, because stream copy normalizes nothing. Convert both clips to matching MP4s first, then merge — an extra step, but the result behaves everywhere I've tried it, from a smart TV to a work laptop. Audio joins along with video at the same seam, so if one recording was louder than the other, level them before merging rather than living with a jump at the splice.