YouTube ad specs — Shorts, in-stream and bumper

There is no such thing as “the” YouTube ad length

A bumper is capped at six seconds — the one hard ceiling Google publishes, with no recommendation attached. Non-skippable in-stream runs fifteen to sixty seconds depending on campaign subtype. Skippable in-stream has no maximum at all, though under three minutes is recommended. In-feed has no maximum. Shorts recommends under sixty seconds without enforcing it.

Any page that answers “how long can a YouTube ad be” with a single number has picked one of those five and dropped the rest.

A recommendation is not a limit, and the difference costs money

Three of the five YouTube durations above are recommendations rather than ceilings. Treating them as limits means re-cutting a clip the platform would have run; treating a real limit as a recommendation means an upload that gets rejected. The checks above say which kind each one is, and a clip over a recommended maximum passes with a note rather than failing.

The accepted resolution floor is well below 1080p

Google recommends 1920×1080 for 16:9, 1080×1920 for 9:16 and 1080×1080 for square, but accepts 1280×720, 720×1280 and 480×480. The file size cap is 256 GB, which is effectively no cap — YouTube is the one platform here where file size will never be the reason an ad is rejected.

Two safe zones, and most campaigns need the stricter one

Google publishes one safe zone for Shorts specifically — 10% top, 25% bottom, 10% right, no left margin — and another for an ad that may serve anywhere on YouTube: 15% top, 35% bottom, 17.8% right, 4.4% left. The second is stricter on every edge.

A call-to-action placed against the Shorts-only zone gets covered the moment the same asset runs in-stream, which is why the wider zone is the safer default for anything that is not Shorts-exclusive.