An Instagram carousel is one post with up to 20 pictures, videos or both, which people swipe through. Scheduling one needs a tool that uses Instagram's publishing API, an Instagram Business or Creator account, and files that pass Instagram's rules, which is where most carousels fail. This page goes through the steps and the places they go wrong. The exact figures are on the carousel size page.
What you need
- A professional account. Instagram's API publishes to Business and Creator accounts. A personal account has to be switched in the Instagram app first.
- JPEG pictures. The API takes JPEG only. A PNG, WebP or HEIC is converted by Preflight, not by Instagram.
- A shape for every slide. Between 3:4 and 1.91:1, the same for all of them.
- A caption of up to 2,200 characters, 30 hashtags and 20 mentions.
Steps
- Connect the account on the Instagram integration page: through Facebook (the connection that can also delete a post) or with Instagram Login.
- Add the files in order. The first slide decides the crop for all the rest, and the order is the order of the swipe.
- Write the caption and, if you want, move the hashtags into a first comment, which is posted straight after the carousel.
- Add alt text to each picture. Instagram takes up to 1,000 characters per picture through the API; see the alt text guide.
- Pick a time and schedule. Preflight creates the carousel at that minute, because Instagram's API has no publish-time field of its own.
- Check the result. The post is read back with its link, and the figures are collected afterwards.
What happens behind the scenes
The API works in two steps. It creates one container per slide, marked as a carousel item, then a parent container of type carousel that lists the children, then publishes the parent. Instagram processes each item, which takes seconds for a picture and longer for a video, so a tool has to wait and poll. A prepared carousel that is not published expires after 24 hours, which is why Preflight prepares it close to the scheduled time. The error codes are in the Graph API guide.
Where carousels go wrong
| Problem | Why | What to do |
|---|---|---|
| A slide is missing | A file is not a JPEG, is over 8 MB, or has a ratio outside the range | Preflight names the file in the composer; fix or remove it |
| Slides look cropped | Every slide is cropped to the first | Use one shape for all slides |
| More than 20 items | Instagram refuses 21 | Split into two carousels |
| A video fails | The frame rate is outside 23 to 60 fps, or it is too long or large | Re-export; see the Reel rules |
| Hashtags over 30 | The API refuses the whole post | Reduce, or move some into a first comment |
Edit and delete
An Instagram caption cannot be edited through the API, in any tool. To correct a carousel you delete it and publish a new one, which loses its likes and comments, and deleting is only possible when the account is connected through Facebook. That is one more reason the checks run before the post: see what you can change after publishing.
Carousels for other networks
LinkedIn takes a document (a PDF) as its carousel: how to post a LinkedIn carousel. TikTok takes up to 35 pictures in a photo post and Threads up to 20; the counts are in images per post. Scheduling carousels works on every plan, the free one included, and over the API.
Steps and limits from Preflight's publishing code and live tests, 30 October 2026.
Questions people ask
- How do I schedule an Instagram carousel?
- Connect a Business or Creator account to a scheduler, add up to 20 JPEG pictures or videos in order, write the caption, and pick a time. The tool creates the carousel through Instagram's API at that minute.
- Can I schedule a carousel with videos?
- Yes. A carousel can mix videos with pictures, up to 20 items. Each video must be 23 to 60 fps and within the Reel length and size.
- Why are my carousel slides cropped?
- Instagram crops every slide to the shape of the first one, 1:1 by default. Use the same shape, 3:4 or 4:5, for every slide.
- Can I edit an Instagram carousel after it is published?
- No, not the caption or the slides through the API. You delete and publish again, and deleting works only for accounts connected through Facebook.
- How many slides can an Instagram carousel have?
- Up to 20. A live publish on 30 October 2026 accepted 20 and refused 21.