Reference · 5 min read
Instagram Carousel Specs Reference 2026: Dimensions, Ratios, File Size, Slide Limit
An Instagram carousel can hold up to 20 photos and videos, and the app keeps a photo at its original resolution up to 1080 pixels wide when its aspect ratio is between 1.91:1 and 3:4. The safest slide is 1080x1350 pixels (4:5), and one orientation applies to every item in the post.
What are the official carousel specs?
| Spec | Value | Where it comes from |
|---|---|---|
| Maximum items | 20 photos and videos, mixed allowed | Help Center (multiple photos), content publishing docs |
| Orientation | One for the whole post: square, portrait or landscape; you cannot choose per item | Help Center (multiple photos) |
| Photo width | Kept as is from 320 to 1080 px; narrower is enlarged to 320, wider is scaled down to 1080 | Help Center (image resolution) |
| Aspect ratio, in the app | 1.91:1 to 3:4, meaning a 1080 px wide photo with height 566 to 1440 px; other ratios are cropped | Help Center (image resolution) |
| Aspect ratio, API (feed image) | 4:5 to 1.91:1; width 320 to 1440 px | IG User media reference |
| File format, API | JPEG only; MPO and JPS not supported | Content publishing docs |
| File size, API (feed image) | 8 MB maximum, sRGB colour space | IG User media reference |
| File formats, web upload | jpg, png, heic and heif | Help Center (post a photo) |
| Crop rule, API | Carousel images are cropped to the first image; default 1:1 | Content publishing docs |
| Reels inside a carousel | Not allowed in the API; videos in carousels are not reels in the app | IG User media reference; Help Center |
| Editing after posting | You can reorder and remove items and edit captions; you cannot add new items | Help Center (multiple photos) |
| Captions and engagement | One caption or one per item; likes and comments attach to the whole post | Help Center (multiple photos) |
| API posts per 24 hours | 100 in a moving 24-hour period, a carousel counting as one post; another section of the same page says 50 | Content publishing docs (the page is inconsistent) |
Which pixel size should a carousel slide be?
| Aspect ratio | Pixel size at 1080 wide | Inside the app range (1.91:1 to 3:4)? | Inside the API range (4:5 to 1.91:1)? |
|---|---|---|---|
| 4:5 portrait | 1080x1350 | Yes | Yes |
| 3:4 portrait | 1080x1440 | Yes, at the taller edge | No, taller than 4:5 |
| 1:1 square | 1080x1080 | Yes | Yes |
| 1.91:1 landscape | 1080x566 | Yes, at the wider edge | Yes, at the wider edge |
1080x1350 is inside both documented ranges, which is why it is the safe default. In 1,064 real slides we measured, 60.3% were 4:5 and 34.1% were 3:4; see the size and slide count study.
Why do the Help Center and the API disagree?
The Help Center says the app preserves photos from 1.91:1 down to 3:4, while the API reference lists 4:5 to 1.91:1 for feed images. We read these as two different surfaces with different limits, and we did not test uploads at the boundary. If you publish through the API, stay inside 4:5 to 1.91:1; if you post in the app, 3:4 is documented as supported. An earlier post of ours said we could not find an official statement of supported ratios; the Help Center page above is that statement.
How do you export a carousel that passes the specs?
- Pick one orientation for the whole deck; mixed shapes are not possible.
- Set the canvas to 1080 pixels wide; for portrait use 1080x1350.
- Export every slide at the same size, as PNG or JPEG. For API publishing export JPEG in sRGB, under 8 MB each.
- Keep the deck at 20 items or fewer, and put the slide you want as the cover first: the first item shows in the feed and sets the crop in the API.
- Check a sample in the app before scheduling a batch.
Is there a best slide count?
The documented maximum is 20. We could not verify an optimal count: every "best number" claim we traced cited no study. In our corpus of 127 decks the median was 9 slides. That describes habit, not performance.
Frequently asked questions
What is the best Instagram carousel size in 2026?
1080x1350 pixels (4:5). It lies inside both the Help Center range (1.91:1 to 3:4) and the API range (4:5 to 1.91:1).
How many slides can an Instagram carousel have?
Up to 20 photos and videos in one post, according to the Instagram Help Center and Meta's content publishing documentation.
Can a carousel mix square and portrait slides?
No. The Help Center says the orientation you choose affects all items in the post and cannot be set per item.
What file size and format does the Instagram API accept for carousel images?
JPEG only, up to 8 MB in sRGB for feed images, with an aspect ratio of 4:5 to 1.91:1 and width up to 1440 pixels, according to Meta's reference pages.
Can you add slides after posting a carousel?
No. You can reorder or remove items and edit captions, but you cannot add new photos or videos after sharing, according to the Help Center.
The Content Engine researches a niche, writes post ideas and renders carousels (PNG) and reels (MP4) on your own computer. USD 67 one time, 7-day refund. It needs a paid Claude plan (Pro or higher), Node.js and FFmpeg, and we have tested it on Windows only.
See the Content EngineSources and our data
- Instagram Help Center: Share a post with multiple photos or videos — opened 2026-10-30; 20-item limit, one orientation, editing after posting
- Instagram Help Center: Image resolution of photos you share — opened 2026-10-30; width and aspect ratio rules
- Meta for Developers: Instagram content publishing — opened 2026-10-30; JPEG only, carousel limits, API post limits
- Meta for Developers: IG User media reference — opened 2026-10-30; Reels and image specifications
- Instagram Help Center: Post a photo on Instagram — opened 2026-10-30; supported web upload formats
- Our own data: 1,064 slides from 127 carousels by 18 accounts, harvested logged out on 2026-10-10; shares recomputed 2026-10-30.
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Keep reading
ReferenceInstagram Carousel Size and Slide Count: What 1,064 Slides Show1080x1350 and 9 slides were the norm in 1,064 measured slides; the official ratio range.
ReferenceInstagram Reels Specs and Safe Zones: Size, Format, Length, CoverReel size, format, length and cover rules, with the safe zones for text.
GuideCarousel vs Reel vs Single Image: A Decision Table by GoalPick carousel, Reel or single image by goal, with a table you can apply in a minute.Facts last verified 2026-10-30 against the sources listed above; pages can change, so check the source before relying on a number. Results vary. No promise of views, followers or income. The Content Engine is an independent product, not made or endorsed by Meta, Instagram or Anthropic. Claude is named only as the tool it runs on.