PostEverywhere Threads API Guide

PostEverywhere API reference for Threads: request fields, the 500 character limit, media rules and request examples.

Publish text posts, image posts, and video posts to Threads (by Meta). PostEverywhere handles Threads' Publishing API to create posts with text and media attachments through a single call. For a general overview of all supported platforms, see the Introduction.

Connect your Threads account to PostEverywhere

Connect Threads from the dashboard with OAuth, or headlessly from code: mint a connect link and hand it to the account owner - no dashboard session needed. Both flows are covered in Connecting Accounts.

What you can post to Threads

Content Type	Media Required	Description
Text post	None	Plain text post, up to 500 characters.
Image post	Image(s)	Post with one or more attached images.
Video post	Video (MP4)	Post with a single video attachment.

Threads is designed for short-form text conversations. Posts are limited to 500 characters, making concise writing essential.

Threads-specific options in the API

Use the platform_content.threads object to customise your Threads post:

{
  "platform_content": {
    "threads": {
      "content": "Threads post (max 500 chars)"
    }
  }
}

Settings Reference

Setting	Type	Default	Description
`content`	string	N/A	Override the default text with a Threads-specific version. Max 500 characters; longer is refused with `400 content_too_long`.

First comments are not available on Threads through the API yet. A firstComment (or first_comment) sent for Threads is removed before the post is saved, and the response notes say so. Multi-part thread_posts are not posted on Threads yet either: a Threads account gets the first part only.

Publish to Threads: a working request

Schedule a Threads Text Post

curl -X POST https://app.posteverywhere.ai/api/v1/posts \
  -H "Authorization: Bearer $POSTEVERYWHERE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Default text for other platforms",
    "account_ids": [2295],
    "scheduled_for": "2026-04-15T12:00:00Z",
    "timezone": "America/New_York",
    "platform_content": {
      "threads": {
        "content": "Hot take: the best social media strategy is being genuinely helpful.\n\nNo growth hacks. No engagement bait. Just answer questions and share what you know.\n\nAgree or disagree?"
      }
    }
  }'

Schedule a Threads Post with an Image

curl -X POST https://app.posteverywhere.ai/api/v1/posts \
  -H "Authorization: Bearer $POSTEVERYWHERE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "content": "Our new feature just shipped!",
    "account_ids": [2295],
    "media_ids": ["e1f2a3b4-c5d6-7890-1234-ef0123456789"],
    "scheduled_for": "2026-04-15T18:00:00Z",
    "timezone": "UTC",
    "platform_content": {
      "threads": {
        "content": "We just shipped bulk scheduling to PostEverywhere.\n\nSchedule up to 50 posts in a single API call.\n\nDocs: https://posteverywhere.ai/docs/quick-start"
      }
    }
  }'

Threads limits: characters, media and video

Requirement	Limit
Post text length	500 characters (longer is refused with `400 content_too_long`)
Image formats	JPEG, PNG, WebP, HEIC
Image max file size	20 MB
Video format	MP4 (H.264)
Video max file size	1 GB
Video duration	Up to 5 minutes
Recommended image ratio	1:1 (square), 4:5 (portrait) or 9:16
Links in post	Supported (auto-previewed by Threads)

Getting better results on Threads

Write for conversation. Threads is built for dialogue. Posts that ask questions, share opinions, or invite debate get significantly more engagement than announcements. End with a question or a take that people want to respond to.
Keep it under 500 characters. Unlike other platforms where longer posts perform well, Threads rewards brevity. Get to the point quickly. A post over 500 characters is refused, so trim it or set a shorter platform_content.threads.content.

Common questions about posting to Threads

Can I attach images or video to a Threads post?

Yes. Upload your media using the Upload Media endpoint, then pass the returned UUID in the media_ids array in your Create Post request. Threads supports images (JPEG, PNG, WebP, HEIC) up to 20 MB and video (MP4) up to 1 GB and 5 minutes long.

What is the character limit for Threads posts?

Threads posts are limited to 500 characters, and a longer post is refused with 400 content_too_long when you create it, not at publish time. Unlike LinkedIn or Facebook where longer posts perform well, Threads rewards brevity. When the same post goes to several platforms, set a shorter platform_content.threads.content for Threads.

X (Twitter) -- similar short-form text post format and conversational style
Instagram -- owned by Meta, visual-first companion platform
LinkedIn -- longer-form professional text posts

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