The master table

PlatformCanvasLength limitFile sizeNotes
TikTok1080 by 1920, 9:1610 min in app; longer uploads on some accounts287.6MB mobile, 4GB webSafe zones: top 120px, bottom 250px, right column
Instagram Reels1080 by 1920, 9:163 min in app; longer uploads possible4GBOver 3 min not recommended to new audiences
YouTube Shorts1080 by 1920, 9:16 or 1:13 min hard limitStandard YouTube limits181 seconds stops being a Short
Facebook Reels1080 by 1920, 9:163 minUnder 1GBClosed GOP 2 to 5s survives re encoding best
LinkedIn16:9, 1:1 or 9:1615 min native5GBWatched on mute; captions essential

The three numbers to memorise

1080 by 1920. 60 seconds. 250MB. A file inside those three numbers publishes everywhere without a warning. Each platform's own page above covers the full detail, including safe zones and the encoding settings that survive each platform's compression.

Why specs cause silent failures

Most failed publishes trace back to something on this page: a file over a limit, a ratio outside the accepted range, a duration the platform rejects, or audio flagged for licensing. The frustrating part is that platforms often reject these at publish time, hours after everyone stopped looking. That is the entire reason SocialPro checks every post against the current specs before the scheduled time and confirms delivery with the platform after it, so a spec problem becomes a fix at 2pm instead of a missing post discovered at 9am.