YouTube Shorts is now serving horizontal 16:9 video ads on desktop devices—a move that could reshape how advertisers approach creative for Shorts placements.

Until now, Shorts primarily showed vertical (9:16) video ads to match the native mobile experience. But YouTube has begun testing horizontal video ad placements (16:9 format) within Shorts on desktop, allowing advertisers to run standard video creatives without the need to reformat for vertical.

Why this matters for advertisers:

✅ Reuse existing creatives – You can now run your horizontal video ads in Shorts inventory on desktop without creating vertical versions.

✅ Expand campaign reach – This update opens up additional Shorts inventory for Video and PMax campaigns, helping scale faster.

✅ Fewer creative barriers – Easier entry into Shorts for brands who haven’t yet invested in vertical-first production.

Heads-up: It’s not fully native (yet)

The horizontal ads currently appear with black bars or visual padding on the sides, which makes the experience feel less seamless for the viewer. That said, if your campaign goal is reach and efficiency over visual perfection, this is a solid opportunity.

Bonus insight:

This format update appears to be rolling out through Performance Max (PMax) campaigns, based on visible UTM tracking data.

Thomas Eccel spotted this update.