Cross-posting one video to TikTok, YouTube, Instagram, Facebook, X, LinkedIn, Threads, Pinterest and Bluesky is mostly the same job nine times, except for the parts that aren't. A field guide to what changes per platform: shape, length, captions, privacy, scheduling and AI labels.
Posting a TikTok as a Reel or a Short is mostly the same video with a few changes that decide whether it works: the watermark, the music, the length, the caption and the cover. A step-by-step checklist, based on what each platform actually says.
The real caption, title and description limits for Instagram, TikTok, YouTube, LinkedIn, X, Threads, Pinterest, Facebook and Bluesky, checked against each platform's own pages, and why a scheduler sometimes cuts off a caption the app would accept.