Vertical video is not one format. Instagram Reels, TikTok, and YouTube Shorts all ship 9:16, but safe zones, caption overlays, and audience expectations diverge enough that resize-after-export costs agencies real hours.
Why presets beat spreadsheets
Onasis ships sixteen platform presets — each locks aspect ratio, resolution, duration, default models, and safe-zone overlays before generation. Producers stop maintaining a Google Sheet of pixel math that goes stale every platform update.
Instagram Reels
The Instagram Reels preset uses 9:16 at 720p with a five-second default. Safe zones reserve roughly 12% top and 18% bottom — room for username chrome and caption stacks. Default pipeline is image-to-video with Flash-tier stills for iteration.
Hook in the first two seconds; CTA in the last frame. That matches how Reels retention curves actually behave in 2026 feeds.
TikTok Vertical
TikTok Vertical is also 9:16, but safe zones skew slightly more bottom-heavy (20%) for sound UI and comment overlays. Trend-native hooks and on-screen text need that headroom — cropping in post is how brands lose text-safe clips at scale.
YouTube Shorts
YouTube Shorts shares 9:16 geometry but uses different caption and subscribe-overlay conventions. The preset applies 8% top and 15% bottom safe zones with title-card and subscribe CTA templates in metadata slots.
When 9:16 is not the answer
Not every drop is vertical. X Video and LinkedIn Video default to 16:9 for discourse and thought-leadership clips. Pinterest Pin Video uses 2:3 — a common miss when teams only export Reels aspect ratios.
Agency batch across formats
Agencies running multi-platform rosters should map each talent’s calendar to presets first, then queue batch work. See platform preset workflow and batch reels for agencies for operational detail.