ThumbGlanceHow we measured
On October 19, 2026 (UTC), we read twelve cards: three different Shorts in each of computer search, a channel’s Shorts tab, mobile web search and a mobile channel’s Shorts tab. The signed-out browser used US region and English, with device pixel ratio 2; viewports were 1280 × 800 and 375 × 812. The pages were this search and this channel tab.
Container readbacks were 216.1875 × 324.28125 CSS px in computer search, 207.59375 × 311.390625 on the computer channel, 167.5 × 251.25 in mobile search and 185.5 × 278.25 on the mobile channel. All were 2:3. Computer titles, views and menus sat outside the picture and were excluded from picture coverage.
We measured element boxes with getBoundingClientRect, clipped text fragments to their visible container and overflow ancestors, and kept the mobile menu’s full 40 × 40 CSS px control box rather than its smaller icon. A 2160 × 3840 image centered with cover in these cards loses 300 canvas px at each vertical edge: use k=max(W/2160,H/3840), then divide visible CSS offsets by k and add the crop offset. The deepest mobile text started 68 CSS px above the card bottom, giving ceil(300 + 68 × 2160 / 167.5) = 1177 canvas px. The menu model occupies a separate top-right 516 × 816 px corner. Our reserved shapes contain every recorded text fragment and menu box across all four sampled surfaces.
The search scrim ran from black at alpha 0.6 at the bottom to transparent at 30% of its host height; the channel scrim reached transparency at the full height. Those hosts spanned the cards. They can dim a picture but are not solid opaque rectangles. The red reserves concern text and menu controls; they do not claim to eliminate all translucent shading.
This is a dated sample from one computer and one browser, not a promise about every card. We did not measure homepage or subscription shelves: the signed-out sessions checked showed no Shorts shelf, and desktop subscriptions requested sign-in. Other countries, signed-in feeds, the YouTube App and TV were not covered. The centered 9:16 cover conversion is a model; prior server transformations of arbitrary uploads and exact glyph, ellipsis and gradient-alpha pixels were not verified.
We also render the longest admitted title fixture (160 characters), 24-character labels, number 99 and a character frame, with default Impact and outline, using the same layout constants as the editor. The live canvas returns these rounded-up edges: Layout 1: placed boxes end at or before x 1557 and y 946. Layout 2: placed boxes end at or before x 1800 and y 2500. Layout 3: placed boxes end at or before x 2160 and y 2277. Layout 4: placed boxes end at or before x 2035 and y 1887. These are geometry bounds, including the outline; actual text can be smaller. Each placed box is checked against both reserved regions before export.