The higher the resolution of a GIF/video fill, the larger the export size. Make sure you're not using a video fill with a higher resolution than is needed for your final export.
🔍 How to check
Export resolution
Select the shape containing the GIF/video fill on the canvas. It's resolution will be shown in a blue box below the shape.
If you're using a plugin export resolution setting other than 1x, the resolution will be the option you select. This will scale down the video so the shortest side matches the selected number of pixels.
Source resolution
Check the resolution of the original file by reviewing it's properties from the folder on your local machine.
🔧 How to fix
Reduce the resolution of the original file to match your export resolution using a free video editing software like iMovie or ClipChamp, then replace the existing video fill shape with the new file on the canvas.
Let us know if there are other video editing tools you recommend so we can share with the rest of the community.
❗ Reminder
Don't change the dimensions of the shape after uploading to the canvas. Sometimes the quality of the final video export may degrade due to scaling limitations.