Video Cutter: Trim MP4 Without Re-encoding

Fast mode cuts on keyframes, so it may start a bit early

Compressed video stores a complete picture (a keyframe) every so often and only the changes in between. Fast mode copies the streams without re-encoding, so the clip has to begin on a keyframe and may start slightly before the point you picked.

Because nothing is re-encoded, fast mode keeps the original quality and finishes quickly even for long videos.

Exact cut re-encodes for a precise start

Exact cut decodes and re-encodes the video, so it can start on any frame. It's slower and, like any lossy encode, changes the picture slightly.

Use it when the first frame matters, such as a clip for a presentation or a moment that starts right after a scene change.

The trimmed file is roughly proportional to its length

With a stream copy, size follows duration: keeping 30 seconds of a 5-minute video gives a file around one-tenth the size, give or take where the keyframes fall and how the bitrate varies across the video.