ig-carousel

Carousels are the highest-dwell format on the grid, because a swipe is an interaction and a scroll is not. They also get a second chance: Instagram can show a carousel again starting from a later slide to someone who did not engage the first time, so slide two has to stand on its own as well.

The format rewards one idea broken into steps. It punishes a caption cut into pieces.

When to use it instead of a Reel

Use a carousel when the idea has sequence and needs to be re-read: steps, a framework with parts, a before and after, a list worth screenshotting. Use a Reel when the idea has motion, a face, or a payoff that has to be seen happening.

If the idea is one claim, it is neither. Hand it to /ig-reel and say so.