How to Schedule Instagram Carousels via API
Create multi-image carousel posts on Instagram using the PostFast API. Schedule up to 10 images in a single swipeable post.
Instagram carousels are multi-image posts that users can swipe through, making them perfect for tutorials, product showcases, before/after comparisons, and storytelling. Carousels consistently outperform single-image posts in engagement.
To create a carousel, include 2-10 IMAGE items in your mediaItems array with sequential sortOrder values. Set instagramPublishType to "TIMELINE" (or omit it since TIMELINE is the default).
Instagram carousels support inviting collaborators to co-author the post, which can significantly expand reach by appearing on both profiles' feeds.
API Parameters
| Parameter | Type | Description |
|---|---|---|
instagramPublishType | string | Type of Instagram post to create TIMELINESTORYREEL |
instagramPostToGrid | boolean | Post to profile grid (for Reels) |
instagramCollaborators | string[] | Array of Instagram usernames for collaboration |
Code Example
const response = await fetch('https://api.postfa.st/social-posts', {
method: 'POST',
headers: {
'pf-api-key': 'YOUR_API_KEY',
'Content-Type': 'application/json'
},
body: JSON.stringify({
"posts": [
{
"content": "The complete guide to building your morning routine (save this!)\n\nSlide 1: Wake up at the same time daily\nSlide 2: Hydrate before caffeine\nSlide 3: 10 min movement\nSlide 4: Review your priorities\nSlide 5: Start with your hardest task\n\nWhich tip are you trying tomorrow?\n\n#morningroutine #productivity #habits #selfimprovement",
"mediaItems": [
{
"key": "image/ig1a2b3c-d4e5-6789-0123-456789abcdef.jpg",
"type": "IMAGE",
"sortOrder": 0
},
{
"key": "image/ig2b3c4d-e5f6-7890-1234-567890abcdef.jpg",
"type": "IMAGE",
"sortOrder": 1
},
{
"key": "image/ig3c4d5e-f6a7-8901-2345-67890abcdef1.jpg",
"type": "IMAGE",
"sortOrder": 2
},
{
"key": "image/ig4d5e6f-a7b8-9012-3456-7890abcdef12.jpg",
"type": "IMAGE",
"sortOrder": 3
},
{
"key": "image/ig5e6f7a-b8c9-0123-4567-890abcdef123.jpg",
"type": "IMAGE",
"sortOrder": 4
}
],
"scheduledAt": "2025-01-31T10:00:00.000Z",
"socialMediaId": "770fa600-04bd-43f6-c938-667877660003"
}
],
"controls": {
"instagramPublishType": "TIMELINE",
"instagramPostToGrid": true
}
})
});
const data = await response.json();
Did You Know?
Tips
Use the first image as a strong hook - it determines whether users swipe
Maintain consistent visual style (colors, fonts, layout) across all slides
Number your slides or add 'swipe' indicators to encourage engagement
End with a clear call-to-action (follow, save, comment)
Portrait (4:5) carousels take up more screen space and typically perform better
Educational carousels and listicles consistently outperform single images
Schedule carousels, Reels, and Stories from one API
Common Pitfalls
Including only 1 image creates a regular post, not a carousel. Include at least 2 images.
Using different aspect ratios across slides causes awkward cropping. Use the same ratio for all images.
Ensure sortOrder values are sequential (0, 1, 2...). Gaps or duplicates may cause unexpected ordering.
More than 10 images will cause an error. If you need more, split into multiple carousel posts.
Frequently Asked Questions
What's the maximum number of images in an Instagram carousel?
Instagram carousels support 2-10 images. You need at least 2 images for it to be treated as a carousel.
Can I mix images and videos in an Instagram carousel?
No, Instagram carousels through the API only support images. For video content, use instagramPublishType: 'REEL' for short-form video.
How do I control the order of images?
Use the sortOrder field in each mediaItem. Set values starting from 0 in the order you want images to appear (0 = first slide, 1 = second, etc.).