Google Performance Max adds support for vertical 9:16 image ads

Google’s Performance Max (PMax) campaigns now support vertical 9:16 image ads, bringing the popular mobile-friendly format to the platform’s most automated campaign type.

What’s new. Google Ads specialist Thomas Eccel spotted the update, noting that vertical “Story Image Ads” – first seen in Demand Gen campaigns earlier this year – are now available in PMax.

Specs at a glance:

• Minimum size: 600×1067 (recommended: 1080×1920)
• Maximum file size: 5MB
• Google hasn’t officially confirmed where these will serve, though in Demand Gen, they appear in YouTube Shorts Image placements.

Why we care. Vertical 9:16 images let PMax campaigns fit naturally into mobile-first environments like YouTube Shorts, where user attention is highest. Experts say this update goes beyond creative specs. As Phil Byrne, founder of Positive Sparks Marketing LTD, noted, it’s about “meeting users where they naturally consume content.”

With Shorts, Reels, and TikTok dominating mobile engagement, vertical formats are key to maintaining attention and relevance.

The bigger picture. Mike Ryan, head of ecommerce insights at Smarter Ecommerce, added that PMax is already monetizing YouTube Shorts through “GMC Image Shorts,” which display multiple product images for remarketing and personalization – a sign that Google is leaning deeper into short-form, shoppable media.