Instagram publishing through the Graph API is older and better documented than most people expect, and most of its surprises are about the account rather than the post: which kind of account, connected which way, decides what can be published and what can be undone. Preflight publishes pictures, carousels, Reels and stories to a professional Instagram account, and connects it either through a Facebook Page or directly. How to schedule Instagram posts is the walkthrough; this page is the integration.
| Instagram through Preflight | What the API allows |
|---|---|
| Text limit | 2,200 characters |
| Media | Pictures and video, up to 10 files |
| Pictures | Accepted |
| Video | 300 MB, 3 s to 15 min, 23 to 60 fps |
| Thread in one go | No |
| First comment | Yes |
| Alt text | Yes |
| Edit after publishing | No, the API has no edit |
| Delete from Preflight | Yes |
| Comments | Read and reply |
| Figures reported | views, likes, comments, shares, saves, reach, watch time, average view duration |
| Retention and traffic sources | No |
What goes out
A picture, a carousel of up to ten pictures and videos, a Reel, or a story. Every video that is not a story goes out as a Reel, because that is the only video Instagram's API publishes. The caption takes 2,200 characters, 30 hashtags and 20 mentions; a first comment can carry the hashtags instead; every picture takes alt text. A Reel can have a cover frame uploaded as its own picture, can be kept off the grid, and can go out as a trial reel. A story is one picture or video with no caption at all, which is why a story is checked by its own rules.
Connecting an account
Two ways, and the difference matters. Through Facebook, you log in with the Facebook account that manages the Page, pick the Page, and the Instagram Business or Creator account linked to it is connected; this is the connection that can also delete a published post. Through Instagram Login, you log into the professional account itself with no Page in between; it publishes, reads comments and figures exactly the same, but Instagram gives this connection no delete, so the Delete button stays off for it. Either way the account must be a Business or Creator account; a personal one has no publishing API.
What is checked before publishing
The rules on /limits/instagram, run on every post. A feed picture must be between 4:5 and 1.91:1 and is refused with its measured size if not; it must be a JPEG up to 8 MB, and a PNG or WebP is converted at publishing rather than refused. A Reel is 3 seconds to 15 minutes, 300 MB, MP4 or MOV, 23 to 60 frames per second, measured when you upload the file. A story video is 3 to 60 seconds and 100 MB, and a story with a caption is warned that the caption is not sent. More than 30 hashtags or 20 mentions is refused, because Instagram refuses it. A Reel setting on a carousel is pointed out as ignored rather than silently dropped. Instagram's own caps on publishes per day apply on top, and are not something a scheduler can lift.
What the API will not do
A published Instagram post cannot be edited; the caption is fixed once it is out, and the only correction is to delete and republish. Delete works through a Facebook Page connection and not through Instagram Login. Comments are read, answered, hidden and deleted, your own and other people's, on both connections; liking a comment through the API is refused by Instagram at the moment, so the heart is off. Figures come back for views, likes, comments, shares, saves and reach, with watch time on a Reel; a story reports views, reach, interactions and replies, and its replies are direct messages rather than comments.
In the API
A carousel, a Reel with its cover and trial flag, a story, the first comment and alt text are all fields in the public API and the MCP server, checked the same way. Instagram is on every plan, including the free one at pricing.
Questions people ask
- Does Preflight need a Facebook Page to post to Instagram?
- No. You can connect a Business or Creator account directly with Instagram Login. A Facebook Page connection is the one that can also delete a published post; everything else works the same both ways.
- Can I edit an Instagram caption after publishing?
- Not through the API, from any tool. Instagram allows deleting published media but has no edit endpoint, so a correction means deleting and republishing.
- Why was my picture refused for its aspect ratio?
- Instagram takes feed pictures from 4:5 portrait to 1.91:1 landscape and refuses anything outside, so Preflight refuses it first with the measured size. Crop it, or publish it as a story, which has no such rule.