Every platform below has its own spec sheet, safe-zone overlay, caption checker and video tools.
9:16 · up to 10 minutes via the Content Posting API; account limits vary
9:16 · current limit not reverified; check the Reels composer
9:16 or 1:1 · up to 3 minutes
16:9 or 9:16 · up to 15 minutes for organic video
9:16 · 4 seconds to 5 minutes for an organic Video Pin
16:9 or 1:1 · up to 2 minutes 20 seconds for most accounts
9:16 · no single Reel length cap in the unified video publishing flow
9:16 · current maximum not established by the Spotlight help page
9:16 or 1:1 · up to 5 minutes
1:1 or 4:5 · depends on the video publishing surface; current limit not reverified