Limits
| Character limit | 500 characters per post. Emoji count as their UTF-8 bytes, so an emoji can use up to 4 characters of the limit. |
|---|---|
| Links | Up to 5 links per post. Threads generates a preview for the first one. |
| Carousels | 2 to 20 images or videos in one carousel post. |
| Image files | JPEG or PNG, up to 8 MB. Threads fetches each file from a URL at publish time. |
| Publishing quota | 250 posts and 1,000 replies per profile in a rolling 24-hour window. A carousel counts as 1 post. |
| Reply chains | A multi-part post publishes as a first post plus replies to it, in order. |
- Write like a conversation, not an announcement. Threads rewards replies and short takes.
- Count emoji carefully: they use more of the 500-character budget than they appear to.
- Use a carousel for a set of screenshots instead of spreading them over several replies.
- Add alt text to every image so the post works for people using screen readers.
- Keep long pieces to 3 or 4 parts; past that, link to a blog post instead.
Scheduling on Threads natively
The Threads app lets you schedule a post from the composer: open the menu next to Post, choose Schedule, and pick a date and time. That works well for posts you write yourself. It has no way for an AI tool to hand over a draft, and no review step between a draft and your followers' feeds.
Scheduling Threads posts with SocialHandoff
In SocialHandoff, an agent such as Claude or a workflow in n8n calls draft_post or schedule_post with the text, any media, and a time. The draft lands in your approval inbox with a Threads preview, a length check that counts emoji the way Threads does, and a flag for any image missing alt text. You approve, reject, request edits, or fix it inline. Only approved posts are scheduled, and an agent can never approve its own draft.
Once an agent has a record of clean approvals, you can promote it on the trust ladder to publish on Threads without waiting for you. A guardrail failure sends it straight back to draft-only.
Why approval matters on Threads
Threads draws on the Instagram audience, and many brands run both from the same account. A clumsy automated post lands in front of the same followers who see your Instagram, so a human read before publishing is cheap insurance.
What SocialHandoff supports on Threads
- Text, image, and video posts, with alt text on images.
- Carousels of 2 to 20 images or videos from one draft.
- Reply-chain threads: each part of a multi-part draft is posted as a reply to the one before.
- 500-character check with emoji counted by bytes, before the draft reaches you.
- Quota check against the 250 posts and 1,000 replies Meta allows per 24 hours, so a busy day defers a post instead of failing it.
- Per-post metrics for views, likes, replies, reposts, and quotes, where Meta returns them.
Threads builds each post from an invisible media container first, and SocialHandoff never resends the final publish call blindly, so a network hiccup does not produce a duplicate post.
Setup notes
You connect Threads through your own Meta developer app with the Threads use case. Meta requires app review before accounts other than the app's testers can post. Tokens last about 60 days, and SocialHandoff renews them in the background before they expire.
Tools, templates, and agent guides
Check whether one draft fits Threads, X, and Mastodon with the cross-post length checker, split a long piece with the thread splitter, and look up media dimensions in the image size guide. Good starting points are the tips thread, how-to thread, and question post templates.
Agent setups for Threads: Claude Desktop for Threads, OpenAI Agents SDK for Threads, Windsurf for Threads, and Zapier for Threads.