Recording one display, one window, and why there is no region capture

iRecord captures one of three things: a full display, a single window, or a connected iPhone or iPad screen.

One display at a time. Full Screen records the display you pick, whichever desktop or Space is showing on it. Two displays cannot be recorded into one take, and a window dragged onto a second display leaves the frame.

Windows come from everywhere. Window mode lists windows from every desktop and Space, grouped by app. A window that is not on screen right now shows its app icon instead of a live preview.

No region capture. Selecting a rectangle of the screen is not offered. It was left out rather than shipped as an option that quietly records the whole display anyway.

What to do instead of a region. Record the full display, then in the editor use the format picker in Save Video to reframe to 16:9, 9:16, 1:1 or 4:5. Reframing letterboxes — it fits the whole picture into the new shape and never crops away part of your screen. To fill the frame with one app, record that app's window instead of the display.