instagram.text.max_graphemes - letmepost.dev

What it checks

countGraphemes(text) <= 2200.

Why 2200

Meta’s Instagram Graph API documents a 2200-character cap on the caption field of a media container. The cap is in user-perceived characters; we count graphemes to match. Empty captions are allowed — see instagram.media.required, which is the constraint that does apply when there’s no media.

Failure response

{
  "error": {
    "code": "preflight_failed",
    "rule": "instagram.text.max_graphemes",
    "platform": "instagram",
    "message": "Caption is 2400 graphemes; Instagram allows at most 2200."
  }
}

Remediation

Trim the caption. Use grapheme-aware splitting — see bluesky.text.max_graphemes for an example.