user-1: I have a relatively small video of a screen recording of about 600kB in H.264 / VBR. Now I wanted to edit some unnecessary parts out. So I edited the clip and exported it, just to discover the size balloons up to 18MB. I used the "Share" button on the top left and an Apple Device 1080p preset.
The result is the same, for iMovie or FCP.
Is there an export method that preserves my original small video size or let me encode in VBR?

user20675: When you click on the share button you will see “Add Destination “. In the window, you see all the possible export formats. 
Formats with “Small” or SD will make the export file size smaller. Try MPEG if your device can play it. 
However, with small file sizes, your tradeoff is low video quality in most cases.

-1: <p>I have a relatively small video of a screen recording of about 600kB in H.264 / VBR. Now I wanted to edit some unnecessary parts out. So I edited the clip and exported it, just to discover the size balloons up to 18MB. I used the "Share" button on the top left and an Apple Device 1080p preset.</p>

<p>The result is the same, for iMovie or FCP.</p>

<p>Is there an export method that preserves my original small video size or let me encode in VBR?</p>
 20675: <p>When you click on the share button you will see “Add Destination “. In the window, you see all the possible export formats. 
Formats with “Small” or SD will make the export file size smaller. Try MPEG if your device can play it. 
However, with small file sizes, your tradeoff is low video quality in most cases.</p>
