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Documentation Index

Fetch the complete documentation index at: https://docs.letmepost.dev/llms.txt

Use this file to discover all available pages before exploring further.

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What it checks

countGraphemes(item.altText) <= 1000.

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Why 1000

Meta’s Threads API docs don’t publish an explicit alt-text cap, so we use the nearest analogue we trust — half of Instagram’s 2200-cap, sized down because Threads alt text is rendered in narrower contexts. The 1000 number is conservative: anything below it has been accepted upstream in our testing. If Meta publishes an explicit cap that differs, this rule will follow.

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Failure response

{
  "error": {
    "code": "preflight_failed",
    "rule": "threads.media.alt_text_max_graphemes",
    "platform": "threads",
    "message": "Alt text is 1240 graphemes; Threads allows at most 1000."
  }
}

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Remediation

Tighten the description. Alt text should describe the image’s content; if you have more to say, it belongs in the post body.