YouTube Shorts

YouTube video metadata has a 100-character title and a 5,000-byte description. This is why a single shared caption is not the right model for Shorts.

Instagram and TikTok

Instagram's publishing caption is limited to 2,200 characters. TikTok video and photo posts use different text fields, and photo fields have distinct limits.

X, Threads, Facebook, and Google Business

X uses weighted character counting. Threads standard text posts allow 500 characters. Facebook Page messages have a much higher ceiling, while Google Business summaries use a conservative 1,500-character product limit.

Keep the reference current

Platform APIs and eligibility rules change. See the sourced Postnchill limits table for references and the last review date.