I occasionally need to trim an MP4 video or split a clip out of the middle. Up to now I've been using a great app called MPEG Streamclip which has all the features I want:

  • super light weight, opens instantly
  • gui for scrubbing through videos
  • keyboard controls for frame-by-frame, keyframe-by-keyframe, in, out, and trim
  • batch list so I can set up multiple splits without waiting for each to save
  • saves clips from MP4s without transcoding

A lot of this functionality was also available in Apple's Quicktime 7 Pro, although not quite as streamlined.

Unfortunately the last update to MPEG Streamclip was in 2012, and each OS update breaks it further. In Mojave the Streamclip GUI is almost useless, and it's 32 bit so 10.15 will kill it entirely. Same for Quicktime 7.

I'm sure I'm not the only person who wants to trim and split video on a Mac. What are the options for lightweight editors to trim MP4s without transcoding?

Edit to explain how this is not a duplicate of Is there an easy way on a Mac to split an audio file at defined intervals?: This question is about splitting a video file, not an audio file, at points decided by scrubbing through the video, not on a defined interval. That question currently has no accepted answer, and the answers that were proposed do not apply to this question.


4 Answers 4


Avidemux is a lightweight editor that can split videos without transcoding:

  1. Start Avidemux
  2. Open a file e.g. by dropping it into the Avidemux window
  3. Choose where your video should start and then click on the (red) “A” button below.
  4. Choose where your video should stop and then click on the “B” button below.
  5. Select an output format (e.g. mp4). Note: there are two mp4 versions. If one does not work, just try the other.
  6. Click on the save icon. Avidemux will propose a new file name based on the old one adding an “_edit” before the suffix. The trimming takes less than a second.
  • I found this software to be awesome for cutting GoPro video between two timestamps, that's exactly what I needed Commented Feb 1, 2023 at 18:50

Movie Splitter

You can split your .mp4 movie without transcoding using Movie Splitter – which I wrote for my own needs.

There is a demo you can download and try.

Miln Movie Splitter for macOS

Splitting and Trimming Custom Sections

Movies can be automatically split by embedded chapter markers, halved into two, or quartered into four. Version 1.4 added the options to let you select custom ranges to be extracted – by scrubbing or through keyboard input for fine grained control.

custom ranges in Movie Splitter for macOS

  • It looks like your tool splits videos either on chapter marks or into halves and quarters. Can it scrub through the video and split on arbitrary frames or keyframes?
    – Robert
    Commented Sep 29, 2018 at 4:50
  • Yes, Movie Splitter can split in custom sections. You can download and try. Commented Sep 29, 2018 at 4:59
  • 1
    Awesome! The screenshot you put in your answer appears to be from a version prior to the addition of the "Custom" button, so that's why I was confused. I tried it out and it works. Thank you!
    – Robert
    Commented Sep 29, 2018 at 5:30
  • 1
    I found it very hard to figure out how to use the keyboard controls to move frame-by-frame. Seems focus is being set wrong. Pressing Left or Right doesn't work half the time. Or it controls the wrong side of the video. Wish it worked easier!
    – pkamb
    Commented Sep 16, 2019 at 7:07
  • 1
    Even still works on High Sierra!
    – bomben
    Commented Aug 26, 2021 at 9:34


https://github.com/mifi/lossless-cut (lightweight)


https://www.shotcut.org (heavy)

  • I had problems with screwed up video at the beginning and end with LosslessCut, probably related to keyframes. Gave up and switched to Avidemux.
    – Robert
    Commented Jun 12, 2019 at 17:56

You can do this (and many other things) with ffWorks. It is actually a GUI for ffmpeg, a really powerful encoding tool.

Just be aware: it costs 19€ and may be a bit more difficult to use, but if you plan to do any more video/audio conversion I can absolutely recommend this software as you can do a lot of things with it.

For trimming without reencoding with ffWorks: select "PassThru" for video and audio codec and add the trim filter. Click "edit" on the trim filter to open a GUI similar to what you described.

For multiple splits I recommend the open source project mkvtoolnix, which can also do many more things than that. It only outputs MKV however, but these can easily be converted to MP4s with ffWorks (without reencoding of course) within few seconds.

  • ffmpeg’s trim is a video filter and as thus cannot operate on the stream without re-encoding.
    – Bombe
    Commented Aug 7, 2022 at 9:27

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