Feed posts
- Square: 1080×1080 — safest default for grid consistency.
- Portrait: 1080×1350 — more feed height, good for type-heavy promos.
- Landscape: 1080×566 — use sparingly; looks small in feed.
Stories and Reels
1080×1920 (9:16). Keep headlines inside the center 1080×1420 box so profile chrome does not cover them.
Carousels
Every slide must share one ratio. Mixing square and portrait in one carousel crops badly. Pick portrait if you want swipe time; pick square for product grids.
Set presets in Poster AI Creator
- Create a project per ratio—do not resize after design.
- Save prompt snippets: "1080x1350 carousel slide 2 of 5, same palette as slide 1."
- Export at 1×; Instagram compresses again—start sharp.
