Start for free
Browse docs▾

Instagram formats

Recommended sizes for Instagram feed posts, carousels, Reels, and Stories, plus safe zones and prompt tips.

Instagram rewards clear vertical-friendly creatives. Use these defaults when you ask the assistant for Instagram content.

Feed post

Best default: portrait 4:5 at 1080×1350.

Why: taller posts take more feed space than square crops. Keep the subject centered; the grid may crop toward a slightly tighter frame.

Useful alternates:

  • 1:1 when you need a classic square
  • 1.91:1 for more landscape, link-style framing (less ideal for organic stills)

How to ask:

  • “Create an Instagram feed post, 4:5, product hero centered, short caption with CTA.”

Carousel

Best default: 4:5, about 7 slides, up to 20 slides max.

Rules that matter:

  • Use the same aspect ratio on every slide. The first slide locks the crop for the rest.
  • Put the hook on slide 1 (title or bold claim).
  • Keep on-slide text large and high contrast.

Alternate: 1:1 if you also cross-post the same assets elsewhere.

How to ask:

  • “Instagram carousel, 7 slides, 4:5, tip series on sleep habits, hook on slide 1, matching style throughout.”

Reel

Best default: 9:16 at 1080×1920.

Duration sweet spot is often under 30-60 seconds (short hooks perform well). Prefer a clear first 1-3 seconds.

In auto-social.io, ask for that total length in chat. Each single clip is snapped to what the video model supports (often up to roughly 15 seconds). Longer Reels are built by generating several clips and merging them. See Chat and generation.

Safe zones: keep critical faces and text away from roughly the top 14% and bottom 20%, where Instagram UI overlays sit. Cover art should also be 9:16.

How to ask:

  • “Instagram Reel, 9:16, about 25 seconds, hook in 2 seconds, on-screen captions, no important text near edges.”
  • “Same Reel with burned-in captions.”

Story

Best default: 9:16 at 1080×1920.

Stories are media-first. Bake titles and CTAs into the image or video. Keep interactive and readable elements away from edges and UI chrome.

How to ask:

  • “Instagram Story, 9:16, bold title in the center, soft CTA above the bottom UI area.”

Caption tips

  • Lead with the most important line; many people only see the preview.
  • Match caption language to on-slide text.
  • Hashtags: use when they help discovery; avoid stuffing.

Common mistakes

  • Mixing ratios inside one carousel
  • Landscape stills that look tiny in the feed
  • Putting the only CTA in the bottom overlay zone on Reels/Stories
  • Asking for a Story as caption-only (Stories need media)

Related