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Documentation Index

Fetch the complete documentation index at: https://help.mirage.app/llms.txt

Use this file to discover all available pages before exploring further.

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How It Works

To remove and replace the background of a video or overlay:
  1. Tap on your video or overlay in the timeline
  2. Tap on Cutout
  3. Select a new background (setting a custom background for an overlay is not possible)
Tap the + icon to set custom stock images or photos from your camera roll as the background.
Animation showing AI background removal and replacement in the Captions app
Last modified on April 20, 2026