Making videos
Short video format and length
Film vertical 9:16 at 1080 by 1920, keep text away from the edges, and aim for videos people finish. For most creator content, 15 to 45 seconds is a good starting range.
One format for every platform
TikTok, Instagram Reels, YouTube Shorts and Facebook Reels all use vertical 9:16 video. Filming once in that format lets you post the same video everywhere.
Safe zones
Each app places buttons and captions over the bottom and right side of the video. Keep faces and on-screen text in the centre so nothing important is covered.
Length
Maximum lengths change as apps update, so check each platform's current limits. For reach, the better question is whether people watch to the end: cut anything that does not earn its place.