From ChatGPT caption to scheduled Instagram post
Ask ChatGPT for the caption and the slot; Postika puts it on your Instagram calendar as pending. You drop in the photo, Reel or carousel and approve.
Instagram publishing specs
Limits Postika checks before scheduling
| Caption length | 2200 developers.facebook.com |
|---|---|
| Hashtags | 30 developers.facebook.com |
| Mentions | 20 developers.facebook.com |
| Images per post | 20 developers.facebook.com |
| Image formats | JPEG developers.facebook.com |
| Image size | 320–1440 px developers.facebook.com |
| Aspect ratios | 4:5–1.91:1 · 9:16 developers.facebook.com |
| Video formats | MP4, MOV developers.facebook.com |
| Min video length | 3 s developers.facebook.com |
| Max video length | 15 min developers.facebook.com |
| Video resolution | ≤ 1920 px developers.facebook.com |
| Max file size | JPEG 8 MB · MP4/MOV 300 MB developers.facebook.com |
| Alt text | 1000 developers.facebook.com |
Official limits from the network's documentation (checked November 5, 2026). Postika enforces its own limits where they are lower.
Step by step
- 1
Describe the post or paste your notes, and tell ChatGPT which Instagram account and time you want.
- 2
ChatGPT writes the caption and creates the post in Postika pending approval.
- 3
If you generated an image in ChatGPT, download it.
- 4
Open the pending post in Postika, attach the image, carousel slides or Reel, check the preview and approve.
Example prompts
- Write a caption for an Instagram post showing our new autumn menu. Friendly tone, one emoji at most, end with 'Book via the link in bio'. Pending approval Friday at 11:30.
- Give me 10 caption ideas for a yoga studio's Instagram in December. Then create the best four as drafts, one per week on Tuesdays at 07:00.
- Create an Instagram post for each of these three product photos I'll upload later: linen shirt, wool scarf, leather belt. Under 600 characters each, pending approval Monday to Wednesday at 19:00.
- Shorten this caption to under 2,200 characters including the hashtags and update it as a new draft.
- What do I have on Instagram in the next two weeks? Show it as a table.
The rules ChatGPT works within on Instagram
Postika tells ChatGPT the limits of each Instagram channel through list_channels and checks every post before accepting it:
| Rule | Postika limit |
|---|---|
| Caption | 2,200 characters |
| Media | Required (photo or video) |
| Carousel | Up to 10 images |
| Video | One per post (Reels) |
Because media is required and ChatGPT cannot send files through the connector, Instagram posts are always created as approval or draft. They show up in your calendar at the planned time, marked as pending. Instagram Stories are not supported in Postika, only feed posts, carousels and Reels. More on formats in Instagram scheduling.
Using images you made in ChatGPT
If you design the visual in ChatGPT, the order that saves the most time is: caption first, image second. Ask ChatGPT for the caption and the post in Postika, then ask it for the image in the same chat so both share the same idea. Download the image, open the pending post in Postika and attach it. The preview shows exactly how the caption and image will look before you approve.
For carousels, ask ChatGPT for one image per slide with consistent style, up to 10. For Reels you will usually edit the video elsewhere and upload it to the post. If your workflow is caption-heavy and based on long documents, the Claude Instagram guide may suit you better. See also carousels.
A weekly Instagram routine with ChatGPT
- Monday: ask ChatGPT "what's on Instagram this week?" and fill any empty day with a pending post.
- During the week: each time you take a good photo, ask for a caption and a slot, then attach the photo.
- Friday: ask for next week's captions in one batch.
All of this is included on every Postika plan, from €29/month for 5 channels (pricing).
Turn ChatGPT into your social media scheduler
- 1
In Postika, create a project and connect the channels you want ChatGPT to use.
- 2
In ChatGPT, open Settings → Apps & Connectors → Advanced settings and turn on Developer mode.
- 3
Back in Apps & Connectors, click Create. Paste
https://postika.app/api/mcpand choose OAuth as the authentication. - 4
Click Create, then click Allow in the Postika window that opens.
- 5
In a new chat, enable the Postika connector from the composer and ask "Which channels do I have in Postika?" to confirm it works.
Frequently asked questions
Can ChatGPT post to Instagram automatically?
Not fully. ChatGPT can create the Instagram post in Postika with caption and time, but you have to add the photo or video in the app, because Instagram requires media and the connector only sends text.
Can ChatGPT schedule Instagram Stories?
No. Postika does not publish Instagram Stories. It schedules feed posts, carousels of up to 10 images and Reels.
Will ChatGPT's hashtags count toward the limit?
Yes. Hashtags are part of the caption, and the whole caption must fit in 2,200 characters. Postika rejects longer captions.
Keep reading
- Instagram scheduler for posts, carousels and ReelsSchedule Instagram posts, carousels and Reels from a weekly calendar. Postika checks the 2,200-character caption and 10-image limit before publishing.
- Turn ChatGPT into your social media schedulerConnect ChatGPT to Postika in developer mode and let it write, schedule and list posts on Instagram, LinkedIn, X and 6 more networks, with your approval.
- Plan your Instagram feed with ClaudeHave Claude write Instagram captions, plan carousels and Reels, and leave them in Postika for you to add photos and approve. Limits checked for you.
- Use ChatGPT to keep your TikTok calendar fullBrainstorm TikTok hooks with ChatGPT, let it create the captions and slots in Postika, then upload your clips and approve. Video or 35-image carousels.
- Post to your Facebook Page from a ChatGPT chatAsk ChatGPT to write a Facebook Page post and publish it now or schedule it. Text-only posts work end to end; photos are added in Postika if needed.