Google Will AI-Resize Your PMax Videos: Opt Out by Sept 4

Google is about to put generative AI between your approved video creative and the people who see it. In an advertiser notice first reported by Search Engine Land on August 17, Google confirmed it is rolling out an asset-optimization upgrade for Performance Max that uses generative AI to extend existing video ads into missing aspect ratios — vertical and square versions of your horizontal video, and shorter cuts — on by default.

Advertisers who don't want it have a concrete deadline: September 4, 2026 to submit Google's opt-out form or work through their account team. After that, Google will generate and serve the missing formats from your existing creative.

This is not a cosmetic editing feature. It changes who controls the final shape of a paid-media message — and for ecommerce teams running PMax (which is most of them in 2026), it's worth a deliberate decision before the deadline, not a default you discover in the reporting tab in October.

What Google is actually changing

The new capability builds on the video enhancements Google already runs in PMax, which convert horizontal videos into vertical and square formats. What's new is the generative layer: instead of simple crops, Google AI can extend a video — filling in the parts of the frame that a crop would lose — to create versions that can serve across more of its inventory. Per Google's documentation on Performance Max video automation, video automation includes both enhancements (created from your existing videos) and auto-generated video ads (created from your images and text when you upload no video). The new generative reframing sits in the enhancements lane.

The stated goal is "to maximize video ad reach while improving the viewing experience" — which is genuinely true for accounts that only have a 16:9 master. Google's own guidance has long said that campaigns with video in all three orientations (horizontal, square, vertical) see materially better performance: PMax accounts with at least one video see an average 12% lift in conversions, and campaigns with at least one video in each of the three orientations deliver 20% more YouTube conversions than horizontal-only accounts (Google's directional benchmarks, published in its PMax guidance).

The catch: a generative reframe is a new creative version of your brand's message, produced without your art director in the room. The upside is reach; the risk is governance.

Why this matters for ecommerce advertisers

For a DTC brand, the video asset is where the offer, the price, and the product promise live. A 16:9 frame may place a logo, price, or legal disclaimer near the edge — and when Google reframes it to 9:16, the generative fill has to decide what happens to that text. Google says enhanced assets go through multiple quality reviews that check for cropped text or logos, poor focus, and loss of the original message — but review is not brand approval. A generated crop that protects the subject can still bury a headline, remove a product detail, or make a regulated disclosure unreadable.

The other risk is product accuracy. Google notes that automatically generated PMax videos can show a different product from the one on the landing page when asset-group and final-URL logic aren't tightly aligned — the same class of problem, now extended to reframed versions of your own video.

None of this means you must opt out. For many accounts, especially smaller teams that only have one orientation, the generative formats are free reach — a 9:16 version of an existing winner costs nothing to produce and can unlock Shorts and vertical placements. The decision is about control, not quality: do you want Google to generate versions of your creative that you haven't seen, or do you want to supply the versions yourself?

What to do before September 4

1. Inventory every PMax campaign with video. Open Campaign settings → Asset optimization → Video and check whether Enhancement is enabled. Unchecking Enhancement disables the feature in-account; if the notice requires a separate opt-out submission, complete that process too and save the confirmation.
2. Decide per account, not per brand. A low-stakes catalog account can let Google generate formats and test the reach. A campaign with hard claims, regulated categories, or high-ticket offers should probably opt out and control the versions. There's no one-size answer — the mistake is not choosing.
3. If you stay opted in, upload native versions first. Google's AI only generates the formats you're missing. If you supply your own 16:9, 1:1, and 9:16 masters, there's no gap for the AI to fill — and the algorithm gets the best possible assets. This is the same "rule of three" we detail in our Performance Max and Demand Gen playbook.
4. Design for the crop either way. Safe zones are now non-negotiable: keep the hook, the product, and the price in the center third of the frame, and put disclaimers somewhere they survive a center-crop. A video that's crop-proof today is a video that survives Google's automation tomorrow.
5. Treat every enhanced file as a new version. If you audit creative (and you should), give generated formats their own IDs in reporting, and compare them against your originals on conversions, not impressions. Google is not going to stop automating creative — the winning workflow is reviewing the output, not fighting the feature.

The bigger picture

Google has spent the last two years moving from automated media buying into automated creative production — first auto-generated video from images and text, now generative reframing of your existing video, and (per this week's announcements) the broader AI Max migration of Dynamic Search Ads. The direction is consistent: advertisers provide the meaning, and the platform increasingly decides how that meaning is rendered.

That's exactly why the September 4 decision matters beyond the checkbox. Teams that treat creative as a controlled pipeline — shipping fresh, crop-safe, multi-orientation video on a cadence — keep the automation working for them instead of around them. And the production economics of that pipeline are the same economics we've written about in our AI video ads cost guide: the bottleneck is no longer rendering, it's the script and hook variety that keeps the asset library fresh.

If your PMax video library is a single 16:9 master shot six months ago, Google's generative reframing will soon be doing a job you should be doing yourself. If your library is a rotating set of crop-safe, multi-orientation assets, the feature is just extra reach. The deadline is the nudge to figure out which one you are — generate the vertical and square versions yourself before the platform does it for you.