Vertical video specs differ across platforms despite one shared shape

What was announced or recorded

Every major short-form platform asks for the same portrait shape, but their spec pages do not ask for the same file. TikTok's Video Ads Specifications page states a vertical recommendation of "9:16, more than or equal to 540*960px," alongside horizontal and square options, and caps non-Spark ad length at "up to 10 minutes" with a file size limit of "less than or equal to 500 MB." YouTube's Get started creating YouTube Shorts help page states a duration ceiling of "up to 3 minutes long" and a resolution ceiling of "a maximum resolution of 1080p," without stating a required aspect ratio in that text. Both pages are living documents describing requirements as retrieved on 16 September 2026, not a dated policy change.

What the documents establish

Read side by side, the two pages establish that "vertical video" is not one interoperable format but a family of platform-specific limits layered on the same rough 9:16 shape. TikTok's page states a minimum pixel dimension and a minimum bitrate ("more than or equal to 516 kbps"), figures aimed at an advertiser assembling a file for an ads manager. YouTube's page is written instead for a creator using the in-app Shorts camera and states a time limit and a resolution ceiling rather than a minimum file spec, since the platform expects most Shorts to be shot and edited on-device. Neither page states a limit matching the other's; a file built to TikTok's advertising floor is not guaranteed to satisfy YouTube's Shorts ceiling, and a Shorts export meets no advertising minimum at all.

Announced versus delivered

Nothing here is an announced policy change; both pages describe standing requirements, and the only "delivery" is whatever file a producer uploads against them. What the documents do not establish is a single cross-platform master spec: a drama distributed through an app, a TikTok ad account and a YouTube Shorts channel needs three separate exports checked against three separate pages, not one file reused three times. That gap is exactly where a production's delivery checklist has to do work the platforms' own documentation does not do for it.

What to watch

Editorially, the detail worth tracking is how often these numbers move: a resolution ceiling or duration limit stated today as a help-page fact is exactly the kind of figure platforms revise without a press release, so a production relying on a cached spec sheet risks working from a stale number. Treating each platform's page as something to re-check per delivery, rather than as a fixed industry standard, is the practical implication of both pages being living documents rather than dated releases.

• Which platform's page was last checked, and on what date, for the specific spec being used?
• Does the export match the platform's stated minimum pixel dimensions, not just its aspect ratio?
• Is the file being reused across platforms without checking each one's separate duration and size ceilings?

A shared aspect ratio disguises how little else these specification pages actually share, and a delivery checklist built on one platform's numbers will not automatically clear another's.