Pinterest video ad aspect check: which Sume ratios fit 1:2 to 1.91:1

Pinterest's standard-width video spec says to avoid ratios shorter than 1:2 (width:height) or taller than 1.91:1, and recommends square (1:1) or vertical (2:3, 4:5, or 9:16) (Pinterest Help, read 2026-10-05). Take the six aspect ratios in the Videos guide's seedance-2 example, convert each to width divided by height, and five land inside the allowed band: only 21:9 (2.333) is out. Two of them, 1:1 and 9:16, are on the recommended list.

The check, ratio by ratio

The allowed band runs from 0.5 (1:2) to 1.91 (1.91:1). Each ratio below is width divided by height, computed to three decimals.

What to request

For a holiday Pin, ask for 9:16 (a Pinterest-recommended vertical) or 1:1. 4:5 and 2:3 are recommended by Pinterest but are not in that seedance-2 example, so a 4:5 Pin needs a different source ratio and a crop, or a model whose catalog lists it. The model catalog is the source of truth: read supported_aspect_ratios from GET /v1/videos/models before you pin a ratio.

Gemini Omni Flash 1.1 makes only 16:9 and 9:16, so 16:9 (1.778) is inside the band but is not on Pinterest's recommended list. 9:16 is the Omni value that is both.

Where a crop fits

Pinterest's recommended 4:5 and 2:3 sit between 1:1 and 9:16. If your model lists neither, generate at the nearest listed ratio with headroom around the product, and crop in your editor. Keep the product in the middle 80 percent of the frame so a crop does not clip it, and put text in the middle band too.

Ratios are the cheapest thing to get right before a render and the most expensive after, since a wrong ratio means a new clip. Read the catalog first, then pin the value in the request body.

Other limits on the same page

The page gives MP4, .MOV or .M4V with H.264 or H.265, a file of up to 2 GB, and a length of at least 4 seconds and at most 15 minutes, with 6 to 15 seconds recommended. Titles can be up to 100 characters with the first 40 typically visible. Descriptions go up to 800 characters but are used by the algorithm and are not displayed in feeds.

A 6 to 15 second clip is inside every length rule. Put the offer in the first 40 characters of the title and burn the shortest version of it into the picture.