Reels, TikTok & YouTube Shorts Video Specs (Plus the Safe Zone No Platform Documents)

These numbers are pulled from each platform's own developer or advertising documentation, not from a generic "social sizes" chart. Instagram's figures come from Meta's developer docs for Reels media. TikTok does not publish resolution or format specs for organic posting, so the numbers below are its own advertising specifications — the most precise public source it offers. YouTube publishes almost nothing about resolution at all, which is itself the most useful fact in this section.

Instagram documents the widest range: Reels can run from 3 seconds to 15 minutes. TikTok's advertising specifications allow up to 10 minutes, though that figure describes ads rather than organic posting, which TikTok does not document with the same precision.

YouTube's limit is the one worth double-checking against older guides: Shorts were capped at 60 seconds for years, but YouTube's own Help Centre confirms that as of 15 October 2024, videos with a square or vertical aspect ratio and a length of up to 3 minutes are categorised as Shorts. Any guide still citing a 60-second ceiling is describing a rule that no longer applies.

Not in the way most "safe zone" charts imply. Instagram's developer documentation and Help Centre cover Reels' technical specs — aspect ratio, resolution, duration, file format — and say nothing about where captions, buttons or a username overlay will sit. There is no official Instagram safe-zone diagram for Reels.

TikTok is the one platform that addresses the question directly, and its answer is more nuanced than a fixed margin: its ad help documentation states that "the safe zone size is determined by the dimension (vertical, horizontal, or square), ad caption length, and any additional formats used," and that longer captions shrink the safe zone further. The only fixed pixel figure TikTok publishes anywhere in this area is a 66×66px safe area for profile photos, which is a different problem entirely. Instead of a margin, TikTok tells advertisers to use its own preview tool before publishing.

YouTube's only documented text constraint sits inside its Shorts advertising specs, not its organic upload guidance: on-screen text is truncated beyond 1 line on mobile and 2 lines on desktop or TV. That is a real, sourced rule — but it governs the Shorts ad unit, not a general safe zone for everyday Shorts uploads.

We could not find an official explanation from any of the three, so treat this as informed reasoning rather than a documented fact. The most likely reason is that the overlay isn't fixed on their end either: caption length changes per video, the username and action-button stack differs by app version and OS, and features like live captions, duets, stitches or pinned comments each claim their own space on top of the frame. A platform publishing a single fixed margin would be publishing something that is already wrong for a meaningful share of its own videos — which is probably why TikTok's documentation explicitly ties its safe zone to caption length rather than giving one number.

Use the platform's own upload preview before you publish — this is literally what TikTok's documentation recommends in place of a fixed margin, and Instagram and YouTube both show a live preview during upload too. It is the only check that reflects the current app, not a template that may already be out of date.

As a general layout habit rather than a documented rule: keep your product and any must-read text away from the very edges of the frame and out of the lower portion, since that is where captions, the caption bar and action buttons consistently stack across all three platforms, even though none of them will tell you exactly how far up that stack reaches.

All three platforms converge on 9:16 vertical as the recommended or defining format, so a single vertical master will play correctly, uncropped, on all of them. What isn't guaranteed is that text baked into that master lands in a safe spot on every platform, since none of them documents matching margins.

The safer split is to keep the video itself platform-agnostic — product centred, vertical framing — and add captions or CTAs per platform close to publish time, rather than hard-baking text near the edges of one master file. Glowya's AI Product Video Generator outputs vertical product video directly in this format, so you are not cropping a horizontal shoot down after the fact and losing the framing it was staged for.