Performance Max Video Specs: Requirements, Sizes, and Limits (2026)

Performance Max accepts video assets in three orientations, horizontal 16:9, square 1:1, and vertical 9:16, and every video must be at least 10 seconds long. Google recommends uploading at least one of each orientation, allows a maximum of 15 video assets per asset group, and requires at least one vertical video between 10 and 60 seconds for your campaign to be eligible for YouTube Shorts. Video assets are YouTube-hosted, so the source video has to be set to public or unlisted. If you upload no video at all, Google auto-generates one from your other assets.

Video is the asset type that trips up most Performance Max advertisers, partly because the requirements are scattered across several Google Ads Help pages and partly because the campaign will happily run without you meeting them. It just runs on a machine-generated video instead. Here is the full spec, checked against Google's own documentation in July 2026, followed by what actually matters when you are putting an asset group together.

What are the Performance Max video specs?

Performance Max video assets must be at least 10 seconds long and come in one of three aspect ratios: horizontal 16:9, square 1:1, or vertical 9:16. Google's own asset specification lists all three orientations at the same minimum, written as "≥ :10". The practical working range is 10 to 60 seconds. You can add up to 15 video assets to a single asset group, and the minimum is one, though video is technically optional because Google will generate one if you leave the slot empty.

One note on the 10-second minimum, because there is a persistent claim online that Google lowered it to 6 seconds. As of July 2026 that is wrong. Google's asset specification page, its video assets guidance, and the Google Ads API asset requirements documentation all independently state 10 seconds. If you build a set of 6-second bumper-style clips for Performance Max, they will not qualify as video assets.

What are the video requirements for Performance Max?

Beyond length and aspect ratio, the requirement that catches people out is hosting. Performance Max video assets are YouTube videos, referenced by URL, not files you upload into Google Ads directly. The source video's privacy setting must be public or unlisted, because Google states that video enhancements only serve when privacy is set to one of those two. A private video will not run.

Google has since added a workaround for advertisers who do not want to manage a YouTube presence. A House channel is a Google-managed YouTube channel you can use when creating a Performance Max campaign, letting you upload a video file during campaign setup without creating or linking your own brand channel. If you have been putting off Performance Max video because nobody owns the YouTube account, that removes the excuse.

What size should a Performance Max video be?

Size in Performance Max means aspect ratio rather than pixel dimensions, and the answer is that you want all three: 16:9, 1:1, and 9:16. Google recommends at least one of each, and its best-practice guidance goes further, suggesting at least three videos in each orientation. The reason is placement coverage. Performance Max serves across YouTube, Display, Discover, Gmail, Search, and Shopping, and different surfaces want different shapes.

Google may also reformat on your behalf. Horizontal video can be scaled into 1:1 or 9:16 for YouTube in-stream and Shorts placements. That is a safety net, not a strategy. Automatic reformatting from a horizontal source usually means crops that cut off the product or the subject's head, which is precisely the kind of creative decision you want to be making yourself.

Does Performance Max require a video asset?

No, video is not strictly required, but skipping it does not mean your campaign runs without video. Google states that if you do not add a video to your Performance Max asset group, one or more videos may be auto-generated from the assets in your asset group, meaning your images, headlines, and descriptions. That generated video then serves in your video placements.

This is the single most important thing to understand about PMax video. The choice is not "video or no video". It is "your video or Google's video". Advertisers who assume they opted out of video by leaving the field blank are usually running machine-generated creative they have never watched. It is worth reading up on how Google's auto-generated Performance Max videos work and how to turn them off before you decide.

How many videos can you add to a Performance Max asset group?

Up to 15 video assets per asset group. The minimum is one if you want to avoid auto-generation, and Google's recommendation is at least one per orientation, so three is the sensible floor. Its best-practice documentation suggests three per orientation, which puts nine in range for a well-supplied asset group.

More is generally better here, within reason. Performance Max is an optimization system, and it needs alternatives to choose between. An asset group with one video gives it nothing to test. That said, do not pad the count with near-identical cuts of the same edit. Distinct angles beat cosmetic variations, because the campaign is trying to learn which argument works, not which color grade you preferred. The same logic applies to any channel, which is why creative testing volume tends to predict account performance better than production polish.

Why the vertical asset matters most

If you only fix one gap, fix the vertical one. Google requires at least one vertical video between 10 and 60 seconds for YouTube Shorts eligibility, and Shorts has become a meaningful share of YouTube ad inventory. Tinuiti's benchmark data, summarized publicly, put Shorts at roughly 21% of YouTube video ad spend in Q4 2025 and around 18% of campaign spend in Q1 2026. That is a large block of inventory your asset group simply cannot access without a vertical asset in the right length window.

It is also the asset most brands do not have. The typical library is one horizontal brand film, occasionally a square cutdown, and nothing shot vertically. Producing vertical video specifically for an ads channel has historically meant a shoot, which is why the slot stays empty and the auto-generated video fills it.

Building the assets without a shoot

This is the gap AdsGen was built for. Paste a product or landing page URL and it writes the hook and script, casts an AI presenter, burns in captions, and renders native vertical 9:16 video ads, several distinct angles in a single pass. Upload them to YouTube as unlisted, add them to your asset group, and the vertical slot is covered with creative you actually chose. You can start a batch with the Performance Max video ads generator.

Be clear-eyed about scope: AdsGen produces vertical 9:16 output, not horizontal or square. It covers the orientation most advertisers are missing and the one gating Shorts eligibility. You will still want a 16:9 asset and ideally a 1:1 alongside it for full placement coverage.

Keep every clip comfortably over the 10-second minimum. A 12 to 20 second vertical ad sits well inside the 10 to 60 second Shorts window and matches how short-form video actually gets watched. Front-load the hook, because the first two seconds decide whether the rest of the ad is seen at all, and it is worth having several different hooks across your set rather than one repeated.

Search themes and the rest of the asset group

Video does not perform in isolation. Performance Max blends your video with headlines, descriptions, images, and the search themes you supply, and weak inputs anywhere drag the whole asset group down. Search themes in particular are worth real attention, since they are how you tell an otherwise opaque campaign what demand you are trying to capture, and thinking them through properly is closer to structured keyword research than to filling in a box.

Group your asset groups the way you group your catalog. One asset group per product line, each with its own video set, headlines, and themes, gives you at least some visibility into what is working. One giant asset group covering everything gives you a black box.

A practical checklist

Before you launch an asset group, confirm each of these. Every video is at least 10 seconds. You have at least one horizontal, one square, and one vertical asset. At least one vertical video sits between 10 and 60 seconds so Shorts inventory unlocks. Every video is hosted on YouTube with privacy set to public or unlisted. You have not exceeded 15 video assets. And you have watched what is actually in the asset group, including anything Google added on your behalf.

That last one takes two minutes and is the check most advertisers skip. Google now surfaces asset-level reporting for automatically enhanced videos across asset group reporting, campaign-level asset reporting, and PMax channel-level reporting, so you can see exactly which videos are serving and where. Look at it before you spend another month assuming the creative in your account is the creative you made.

Once the specs are handled, the remaining work is supply: enough distinct vertical video to give the campaign something to optimize. That is a production problem more than a media-buying one, and it is the part you can now solve from a product URL rather than a call sheet. If you run Google video beyond Performance Max, the rules are not identical: the Demand Gen video specs allow a lower 5 second minimum and add a 4:5 aspect ratio, so check both before you brief one edit to cover every Google campaign.