Video aspect ratios for TikTok, Reels & Meta ads: what actually fits each placement

Every major ad placement treats exactly one aspect ratio as native, and it is not the same ratio everywhere. TikTok renders 9:16 edge to edge, Instagram and Facebook feed favor 4:5, and Meta carousel cards are 1:1. Ship one file to every placement and at least one of them will letterbox, crop, or shrink your video. Here is what each placement actually renders, where the interface sits on top of your pixels, and what it costs you when the ratio is wrong.

The cheat sheet

Placement	Native ratio	Render at	Notes
TikTok in-feed	9:16	1080×1920	Any other ratio is letterboxed in the feed
Instagram Reels / Stories	9:16	1080×1920	Top ~14% and bottom ~35% sit under UI overlays
Instagram / Facebook feed	4:5	1080×1350	1:1 (1080×1080) also native; 16:9 renders smallest
Meta carousel cards	1:1	1080×1080	Each card can be an image or a video
YouTube Shorts	9:16	1080×1920	Fullscreen vertical
YouTube in-stream	16:9	—	Standard horizontal player

The rest of this guide unpacks the rows people get wrong most often.

TikTok: 9:16 or you get letterboxed

TikTok's feed is a fullscreen vertical surface, and the native ad format is 9:16 at 1080×1920. Upload anything else and the feed letterboxes it: your video floats in the middle of the screen with dead space filling the rest. A square 1:1 clip gives up the top and bottom of the display to padding; a horizontal 16:9 clip becomes a thin strip.

That matters more on TikTok than almost anywhere else because everything around your ad is edge to edge. Users scroll a wall of fullscreen video, and a letterboxed ad reads as "ad" before a single frame of your hook plays. If you only produce one master version of a creative, produce it at 9:16 — it is the ratio every other vertical placement can be reframed from.

Reels and Stories: 9:16 with a safe-zone catch

Instagram Reels and Stories are also 9:16, so it is tempting to treat them as the same placement as TikTok. The ratio is the same; the usable frame is not. On Reels, roughly the top 14% and the bottom 35% of the frame sit under interface elements: the account name up top, and the caption, audio attribution, and action buttons stacked along the bottom.

That bottom 35% is exactly where many TikTok-first creatives put their burned-in subtitles and their end-card CTA. Run the same file on Reels and your subtitles fight the caption overlay while your CTA hides behind the action bar. The fix costs nothing at edit time: keep text, product shots, and anything the viewer must read inside the middle band of the frame. Faces and motion can bleed into the overlay zones; words and buttons cannot.

Facebook and Instagram feed: 4:5 is the workhorse

Feed is where the most quiet waste happens, because feed is not a fullscreen surface and vertical instincts stop applying. For Instagram and Facebook feed video, 4:5 at 1080×1350 is the primary recommendation. 1:1 at 1080×1080 is also natively supported and perfectly serviceable. 16:9 is the one to avoid: it renders with the smallest footprint of the three on a mobile feed.

The reasoning is pure geometry. Feed placements share the same width, so height decides how much screen you occupy. At the same width, a 4:5 video is more than twice as tall as a 16:9 video, which means more than twice the screen under the viewer's thumb at the exact moment they decide whether to stop scrolling.

And no, you cannot just push your 9:16 TikTok file into feed and let the platform sort it out. A 9:16 asset in a 4:5 placement gets cropped or letterboxed to fit, and either outcome hurts: cropping can cut off faces, on-screen text, or the product itself, while letterboxing shrinks you back down to the small footprint you chose 4:5 to escape.

Meta carousels: 1:1, no exceptions

Carousel cards on Meta render at 1:1, and each card can be an image or a video. If a carousel is part of your plan, frame for a square from the start: center the subject, keep text away from the edges, and assume anything composed for the top or bottom third of a vertical frame will not survive the trip.

YouTube: two placements, two ratios

YouTube is really two different surfaces. In-stream ads run at 16:9, the standard horizontal player. Shorts run at 9:16, fullscreen vertical like TikTok. They are not interchangeable: a vertical file in the in-stream player and a horizontal file in Shorts both end up boxed into a fraction of the screen. Treat them as separate placements with separate exports.

What a wrong ratio actually costs

Most aspect-ratio guides stop at the spec table. The part that should change how you ship creative is what a mismatch does in practice:

• Cropping deletes information. An automatic center-crop does not know where your subtitles, your product, or a human face lives in the frame. Whatever falls outside the placement's window is simply gone, and nothing warns you.
• Letterboxing shrinks you. Occupied screen area is the first lever of thumb-stop; it acts before your hook, before your first line of text, before anything creative you did. A letterboxed video concedes that lever on every impression it serves.
• Overlay collisions bury your message. Right ratio, wrong layout: 9:16 on Reels with subtitles in the bottom 35% means the platform's UI sits on your words for the entire runtime.

This tax compounds with volume. Paid social already demands a steady stream of fresh creative (see how many ad creatives you actually need per week), and if every batch ships in a single ratio, every placement except one pays the mismatch tax on every variant. It also muddies your performance reads: a feed placement that underdelivers because it serves a letterboxed 9:16 file looks, in the dashboard, exactly like creative fatigue. Before you retire a creative for fatigue, check what it actually looks like rendered inside each placement.

One winning video, every framing

The honest objection to all of the above is production cost. If 9:16, 4:5, and 1:1 each need their own version, every creative becomes three or four exports: re-cropped, re-checked against safe zones, re-rendered, re-uploaded. Multiply that by the weekly volume paid social expects and most teams quietly give up and ship one ratio everywhere.

This is the step worth automating instead. With riffkit, you produce a winning 9:16 riff once, then reframe it to 3:4, 1:1, or 4:5 — the output is near frame-identical, only the framing shifts, and each ratio bills as one video, with 1080p available when the placement warrants it. One creative decision, every placement served natively. If you are starting from a Reel that already proved itself, recreate the winning formula at 9:16 first, then reframe outward from there, or start a riff now and take the ratios from the same run.

Before you launch: a 60-second ratio check

• One master at 9:16, 1080×1920, for TikTok, Reels, Stories, and YouTube Shorts.
• On Reels and Stories, keep essential text and CTAs out of the top ~14% and bottom ~35% of the frame.
• A dedicated 4:5 (1080×1350) version for Instagram and Facebook feed, never an auto-cropped 9:16.
• 1:1 (1080×1080) for Meta carousel cards, framed from the center out.
• 16:9 for YouTube in-stream, 9:16 for Shorts, never swapped.
• Preview every placement before spend goes live. Thirty seconds of checking beats a week of quietly letterboxed delivery.