Validate post content
Dry-run the full post validation pipeline without publishing. Catches issues like missing media for Instagram/TikTok/YouTube, hashtag limits, invalid thread formats, Facebook Reel requirements, and character limit violations. Accepts the same body as `POST /v1/posts`. Does NOT validate accounts, process media, or track usage. This is content-only validation. Returns errors for failures and warnings for near-limit content (>90% of character limit).
API key authentication - use your Late API key as a Bearer token
In: header
Post text content
Target platforms (same format as POST /v1/posts)
Root media items shared across platforms
Response Body
application/json
curl -X POST "https://getlate.dev/api/v1/tools/validate/post" \ -H "Content-Type: application/json" \ -d '{ "platforms": [ { "platform": "youtube" }, { "platform": "twitter" } ] }'{
"valid": true,
"message": "No validation issues found.",
"warnings": [
{
"platform": "string",
"warning": "string"
}
]
}Validate post character count POST
Check weighted character count per platform and whether the text is within each platform's limit. Twitter/X uses weighted counting (URLs = 23 chars via t.co, emojis = 2 chars). All other platforms use plain character length. Returns counts and limits for all 15 supported platform variants.
Check subreddit existence GET
Check if a subreddit exists and return basic info (title, subscriber count, NSFW status, post types allowed). Uses Reddit's public JSON API (no Reddit auth needed). Returns `exists: false` for private, banned, or nonexistent subreddits.