Is Google AI-Resizing Your Performance Max Videos? Here’s What to Do Before September 4

Google is now using generative AI to automatically create missing video formats inside your Performance Max campaigns. Here is what that actually changes and how to respond before the opt-out window closes.

If you run Performance Max campaigns and have not yet heard about this, you need to read it today. On August 18, 2026, Google confirmed it is rolling out a generative AI feature that takes your existing video assets and creates new versions in the aspect ratios your campaign is missing. Horizontal-only? Google will generate a vertical and a square version. That content then runs across additional placements you were previously missing out on.

That sounds helpful on the surface. And for some advertisers, it probably is. But for agencies managing brand-sensitive campaigns or clients with strict creative guidelines, this is not a passive upgrade you can ignore. The deadline to opt out is September 4. After that, the feature runs automatically unless you change your account settings, which Google says you can still do at any time.

Here is what you actually need to know.

Why Is Performance Max Hard to Control?

Performance Max has always been a tension between automation and oversight. Google manages placements, audiences, and now increasingly creative. The pitch is always efficiency. The catch is that every layer of automation you accept is a layer of creative control you hand back to Google’s models.

This video resizing feature is the latest example. It builds on Google’s existing enhancements that can already flip a horizontal video into a vertical or square format by cropping or letterboxing. What is new is the generative AI layer, which goes beyond simple cropping. Google’s models are now generating new visual content to fill in what a standard resize would otherwise cut off or leave blank.

Think of it this way: if your video has a speaker on the left side of a 16:9 frame, a simple crop to 9:16 might cut them out entirely. The generative approach tries to reconstruct the frame so the subject stays centered. That sounds impressive. The risk is that it can also generate backgrounds, fill edges, or adjust visual elements in ways that do not match your brand, and you will not necessarily see it before it runs.

What Did Google Actually Announce?

According to TechBriefly, which first reported the announcement on August 18, the feature was spotted by JXT Group founder Menachem Ani, who shared the communication he received from Google on X. Google confirmed the rollout is live and applies to existing Performance Max video assets across campaigns.

The stated goal is to maximize video ad reach by generating the aspect ratio variants advertisers have not uploaded themselves. Performance Max campaigns serve across YouTube, Google Display Network, Gmail, and Discover, each of which uses different video dimensions. The three standard orientations are horizontal 16:9, square 1:1, and vertical 9:16. If your asset group only has one or two of these, Google’s AI now fills the gaps.

For advertisers who do not want this applied, Google is offering two paths: contact your account management team, or submit an opt-out form before September 4. After that date, the feature stays on unless you change the setting yourself inside the account.

Should You Opt Out or Let It Run?

The honest answer is that it depends on your situation, and there is no single right call. Here is how to think through it.

Lean toward letting it run if:

Your current asset groups only include a single video orientation. If you uploaded one 16:9 video and that is it, Google is already generating other formats anyway through its older enhancement tools. The generative layer is a step up in quality compared to basic letterboxing, and missing vertical inventory on YouTube Shorts and mobile placements is costing you reach. For direct response campaigns where brand aesthetics are secondary to volume and cost efficiency, the tradeoff is usually worth it.

You do not have the production resources to create multiple aspect ratio versions of every video. Smaller teams and brands with limited creative budgets are exactly who this feature was built for. If the alternative is simply not having vertical or square formats at all, automated resizing is better than a gap in coverage.

Lean toward opting out if:

Your brand has strict visual standards. Fashion, luxury, financial services, pharma, and premium consumer brands often have precise frame compositions, talent placement, and visual continuity requirements that AI resizing cannot reliably replicate. The risk of a generated frame that looks off-brand or distorts a face or product is higher than the cost of missing a placement.

You have on-screen text or graphics that sit close to the frame edges in your original video. Generative AI resizing can shift or partially obscure supers, lower thirds, and captions when recomposing the frame. If your horizontal video has a call to action at the bottom right, a vertical reframe might bury it.

You are running campaigns where your client or legal team needs to approve every creative before it goes live. Any AI-modified asset that runs without pre-approval creates a compliance problem regardless of how good it looks.

How to Review Your Videos Before September 4

Even if you plan to keep the feature on, do a quick audit of your existing Performance Max video assets now. Here is a fast checklist:

Check what orientations you have

Go to your asset groups in Google Ads and look at your video assets. If you have all three orientations (16:9, 1:1, 9:16) uploaded already, the AI resizing feature has less to do. It primarily kicks in when orientations are missing.

Look at where your important visual elements sit

Watch your existing horizontal videos and note where the key content lives in the frame. Subjects and text that are centered tend to survive a reframe well. Edge-heavy compositions are higher risk.

Check for on-screen text and supers

Text elements close to the edges of a 16:9 frame are the most common thing to get clipped or repositioned in a vertical reframe. If your videos have brand names, prices, or calls to action displayed in the lower thirds or corners, that is a signal to either opt out or upload your own vertical version with those elements repositioned.

Upload your own vertical and square versions if possible

If you have the source files and a few hours of production time, uploading properly composed 9:16 and 1:1 videos yourself is the best outcome. Google’s AI resizing only activates for missing orientations. Your own assets always take priority.

Common Mistakes to Avoid

Waiting until after September 4 to think about it is the most common one. The opt-out window is short, and if you manage multiple client accounts, you need to make a decision per account rather than a blanket call.

Treating this as an all-or-nothing choice is the second mistake. You can opt out at the account level and still upload your own vertical videos later if you want to. Opting out does not disable any features, it just stops Google from generating formats you have not explicitly provided.

Assuming the AI output will look wrong is also worth pushing back on. Google’s generative resizing is meaningfully better than what it was doing with simple cropping a year ago. For many campaigns, especially broad awareness formats, the quality will be acceptable. Do not opt out purely out of skepticism without actually seeing what the feature produces for your content type. If you have an account manager, ask them to show you a preview.

At Incisive Growth, we handle Performance Max asset strategy for clients across e-commerce, services, and D2C brands. The question of when to let Google’s automation run and when to hold the line on creative is one we navigate in almost every campaign. Our Google Ads management service includes regular asset audits so these kinds of changes get caught before they affect performance.

What This Means Going Forward

This is part of a clear pattern in how Google is building Performance Max. Every few months, another layer of creative control shifts from advertiser to algorithm. AI voice-overs landed in early 2026. AI-generated shopping descriptions rolled out in mid-year. Now video resizing. The direction is not subtle.

That does not mean you should fight it at every step. It means you need to be deliberate about which automation layers you accept and which ones you actively manage. The advertisers who do well inside Performance Max in 2026 are the ones who provide high-quality creative in every format Google needs, so the platform does not have to fill in the gaps with AI. When you give Google enough raw material to work with, the automation runs better. When you leave gaps, Google fills them, and you have less say over what that looks like.

The September 4 deadline is a prompt to review your video creative strategy, not just a checkbox. Use it as one.

Frequently Asked Questions