Start with the final shape
A portrait 9:16 canvas gives text less horizontal space than a landscape frame. Choose your output format before refining caption size and line breaks. LocalCaptions displays detected source dimensions and changes the preview to the selected canvas.
Keep text easy to follow
Use shorter phrases, a legible font and adequate contrast. A large type size can create too many lines; a small size can disappear on a phone. Read the captions at the size your audience will actually see.
Leave space for platform controls
Social platforms place navigation, account names and other controls over video. Their layouts can change. Keep important words away from the extreme edges and bottom, and check the destination’s current preview before publishing.
Understand fitting and padding
LocalCaptions fits the entire source within the output canvas. A landscape source inside portrait output will have padding. Choosing 9:16 does not automatically crop a landscape subject into a full-height portrait shot. Reframe footage in a video editor first when that is your intended composition.
Verify the export
Portrait output is 1080 × 1920. Check a rendered frame, export the MP4 and watch it on the destination device. Review timing, line wrapping and position over several scenes.