Carousel Post

What is a carousel post?

A carousel post is a single feed post that contains multiple cards (images, videos, or a mix) that the viewer swipes through in sequence. Each platform calls them slightly differently: Instagram and Threads call them carousels, LinkedIn calls them document carousels (though plain image carousels also exist), TikTok calls them photo posts when used with images, X calls them image-set posts. The user experience is similar: tap or swipe to move through cards, with the post showing as one item in the feed.

Why carousels outperform single posts

Three reasons. First, carousels increase dwell time — every swipe is an additional second of attention, which the algorithm interprets as engagement. Second, carousels often get re-shown to users who didn't engage with the first slide; the algorithm gives carousels multiple at-bats. Third, carousels are saved more often than single posts because users save them as future reference (recipes, tutorials, infographics). Saves are weighted heavily by Instagram's algorithm in particular.

Industry benchmarks: Instagram carousels average 1.5-2x the engagement rate of single images, and 1.3-1.6x of Reels for educational content. The format works best for tutorials, before/after demonstrations, list posts (Top 10 X), step-by-step guides, and product showcases.

Per-platform rules and slide counts

Instagram supports 2-10 slides per carousel, mixing images and videos freely. The first slide acts as the cover and determines the thumbnail in feed. Aspect ratios should match across slides for a clean swipe experience. LinkedIn supports up to 10 image slides or a separate document-carousel format (PDF upload, up to 300 pages — yes, really). X supports up to 4 images per post (no video carousels). Threads supports up to 10 images. TikTok photo posts support up to 35 photos. Facebook supports up to 10 images per album-post. Pinterest does not support carousels in the traditional sense — each pin is one image — but offers carousel-style 'video pins' with up to 60 seconds of looped clips.

How to design a carousel that performs

Five practical rules. (1) The first slide is your hook — write a strong text overlay that creates curiosity. (2) End with a call-to-action slide — 'Save this for later' or 'Comment X for the link'. (3) Keep slide aspect ratios identical — mixing 1:1 and 4:5 looks janky. (4) Use slide numbering (1/7, 2/7, etc.) to set expectations. (5) Optimize alt text per slide for accessibility and SEO — Instagram's algorithm reads alt text for content classification.

Carousel limits and behaviour by platform

Publish an Instagram carousel via REST API

json

// POST /v1/posts
{
  "profile_name": "main",
  "platforms": ["instagram"],
  "post_type": "carousel",
  "media_urls": [
    "https://cdn.example.com/slide1.jpg",
    "https://cdn.example.com/slide2.jpg",
    "https://cdn.example.com/slide3.jpg",
    "https://cdn.example.com/slide4.jpg"
  ],
  "description": "5 lessons from launching a SaaS in 2026.\n\nSwipe through →",
  "instagram_media_type": "CAROUSEL",
  "instagram_alt_text": "Cover slide showing the headline 5 lessons from launching a SaaS",
  "instagram_cover_url": "https://cdn.example.com/slide1.jpg"
}

Frequently asked questions