DOOH creative spec reference

DOOH has 50+ screen types, so one creative gets transcoded, resized and letterboxed across them — but you still build to spec, and the specs differ by platform. This reference gathers the verified build requirements for the major DOOH supply platforms, plus the two universal rules that catch most newcomers: build silent, and build vertical.

The per-platform table

Build to the supply platform you’re transacting through. Verified specs (platform docs — primary/directional):

Platform	Static	Video	HTML5	Notes
The Trade Desk	D6 vertical 1080×1920, JPG/PNG	MP4	—	D6 is the cross-SSP reach format
Ströer	—	MP4 / H.264, no audio, 5–30 s, ≤12 Mbps, 16:9	—	The canonical no-audio spec
Vistar	JPG, ≤10 MB, text ≥15 px	MOV/MP4, ≤50 MB	Not accepted	Transcodes/letterboxes; DCO → static image
Hivestack	JPG/PNG	MP4/MOV, under 10 MB	—	Common dims 1920×1080, 1080×1920, 1280×720
Broadsign	PNG/JPEG (no animated GIF)	MP4/MOV/WebM, H.264 ~8 Mbps	Supported (Chromium v87+)	No published platform-wide file-size cap

A figure to ignore: a “Broadsign 750 KB max” limit circulates but could not be verified in Broadsign’s own docs — caps in DOOH are usually per-network, so confirm rather than design to an unverified number.

The two universal rules

Whatever the platform, two rules hold across DOOH and trip up most first builds:

Silent by default. DOOH is experienced without sound — platform specs are explicit (e.g. Ströer’s public-video spec is no audio track). Carry the message in type and captions, never voice-over. In a salon this is doubly true: the venue owns its own ambience.
Vertical first. Portrait 1080×1920 (9:16) is the dominant panel format and the natural build for a mirror or styling-station screen. Make it the master; supply a landscape 1920×1080 variant for lobby and standalone screens.

One master, many screens

You don’t build a file per screen — platforms run a transcoding service that resizes and letterboxes one master across similar aspect ratios (Vistar — primary). The practical consequences:

Keep critical content in a safe area. A logo or QR jammed to the edge can be cropped when the asset is re-fit to a different screen shape.
Design for legibility at distance. Keep text large — Vistar specifies a ≥15 px minimum height — and high-contrast, because the same asset may render on a small mirror screen or a large lobby display.

Dynamic creative: design the static frame

Contextual and dynamic creative (daypart, weather, nearest-store, promos) lifts outcomes, but the production reality constrains the build: many platforms render dynamic creative to a static image at serve time, animated dynamic creative is region-limited, and raw HTML5 is often not accepted (Vistar — primary). So design each DCO variant as a static layout that stands on its own — don’t assume live animation will play on the panel. (The creative craft around these specs is in Creative for salon & mirror screens.)

Methodology & caveats

Verified (primary): portrait 1080×1920 as the dominant build and the transcoding/letterboxing reality, the ≥15 px text minimum, JPG ≤10 MB / video ≤50 MB, HTML5-not-accepted and DCO-renders-to-static facts from Vistar; the D6 1080×1920 format from The Trade Desk; the MP4 / H.264 / no-audio / 5–30 s / ≤12 Mbps spec from Ströer; Broadsign’s supported formats (PNG/JPEG, MP4/MOV/WebM, HTML5 via Chromium 87+) from Broadsign docs. Directional: Hivestack’s under-10 MB cap and common dimensions (via reseller restatement); the “~90% of panels are portrait” figure. Not asserted: a “Broadsign 750 KB” file cap (not in Broadsign’s own docs — per-network caps apply). Specs change; confirm against your supply platform’s current creative guidelines before delivery.