The master table
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.