Performance Max asset groups: setup, creative requirements, and how video assets affect delivery

Asset groups are the creative payload that feeds a Performance Max campaign: themed bundles of text, images, logos, and optional video that Google’s systems assemble into ads across Search, YouTube, Discover, Maps, and more. This doc stays at the asset group layer: exact specs, how Ad Strength works, what happens with video (supplied or not), and how to structure groups so you hit Excellent without junk assets.

What asset groups are and how Google uses them

Per Google’s documentation, asset groups are collections of creative assets centered on a theme or target audience, and Google’s AI mixes and matches those assets to render ads across all eligible inventory. The system chooses combinations of headlines, descriptions, images, logos, and videos from the group to fit each placement and user context. [1]

Google also states that the published minimum counts in the specs table are those required to publish an asset group when no Merchant Center feed is attached. With a feed, those minimums no longer gate publishing, and feed-only Performance Max setups can skip manual text, image, and video assets entirely. Once you add manual assets to a feed-based asset group, they cannot be deleted to return to a pure feed-only state. [2]

This corrects two common misunderstandings: minimum counts do not always apply the same way, and one asset group is not meant to cover every product. Google’s best practices say to organize asset groups around a specific theme or target audience, such as product or service lines, instead of a single group for the whole catalog. [2][15]

Text asset specs and counts

Headlines in Performance Max asset groups can be up to 30 characters, and Google’s specs require at least 3, with at least 1 headline of 15 characters or less. There are 15 headline slots in total, and Google recommends using 11 or more to improve Ad Strength. [3]

Long headlines can be up to 90 characters. You must provide at least 1 long headline, can supply up to 5, and Google recommends 2 or more. Descriptions also have a 90 character limit, require at least 2 assets, allow up to 5, and Google recommends using 4 or more. [4]

Business name is a separate required text field, up to 25 characters, and Google states it must exactly match either the domain name or a legally verified business name. Call to action is a single field that is automated by default or can be selected, and display URL paths allow up to 2 segments of 15 characters each. Google notes that in double width languages, each character counts as 2 toward these limits. [5]

Google’s Ad Strength guidance clarifies that filling all 15 headline and 5 description slots with near duplicates does not align with what the rating measures. Ad Strength evaluates variety and coverage, and Google’s own data attributes about 6% more conversions on average to advertisers who improve Performance Max Ad Strength from Poor to Excellent, but this is internal aggregate data, not a guarantee for any single account. [12][13][14]

Image and logo requirements

Google’s specs require at least 1 horizontal and 1 square image per asset group. Horizontal images must be 1.91:1 ratio, with 1200x628 pixels recommended and 600x314 as the minimum, while square images must be 1:1 ratio, with 1200x1200 recommended and 300x300 as the minimum. Vertical images are 4:5 ratio, with 960x1200 recommended and 480x600 as the minimum, and are optional. [6]

Across all image ratios, Google allows up to 20 images per asset group, recommends 4 or more per required ratio, and supports .jpg or .png formats up to 5120 KB. Logos must include at least 1 square 1:1 file, with 1200x1200 recommended and 128x128 as the minimum. Horizontal 4:1 logos are optional, with 1200x300 recommended and 512x128 as the minimum, and Google notes that transparent logo backgrounds may render on white. [6][7]

These specs apply regardless of whether you also use a Merchant Center feed. For retail advertisers, how feeds and images interact is covered separately in business-type focused guidance, but the asset group image and logo requirements themselves follow the same ratios and sizes.

How video assets work and what happens if you skip them

Google’s Performance Max specs list video as an asset type with 3 orientations: horizontal 16:9, square 1:1, and vertical 9:16. Each video must be at least 10 seconds long, and you can upload up to 15 videos per asset group. The specs table explicitly marks video as not required, which corrects the misconception that video is mandatory for Performance Max. [8]

However, Google also documents that if no video is added to an asset group, one or more videos may be auto-generated from the assets in that group. These auto-generated videos are built from your existing images, text, and logos, and they can run across video inventory such as YouTube. This corrects the misconception that Google will not run video you did not explicitly create. [9]

Google’s own guidance states that to prevent auto-generated AI videos and to help achieve Excellent Ad Strength, you should upload your own custom videos in all 3 orientations or build them using the Asset Library video creation tool. Auto-generated video can also be controlled at the campaign level through a setting. [10]

Preventing auto-generated video and Google’s caution

The documented prevention path for auto-generated video has two parts. First, upload your own videos in horizontal 16:9, square 1:1, and vertical 9:16 orientations, each at least 10 seconds long, so the system has complete coverage with your creative. Second, use the campaign level setting that controls auto-generated video to disable it if you do not want Google to create additional videos. [8][10]

Google’s help content cautions advertisers to ensure that products featured in generated videos align with the landing page inventory, because discrepancies can lead to poor user experiences. This caution applies both to auto-generated videos and to any videos you build with Google’s tools, since mismatched creative and landing pages can confuse users. [11]

In practice, this means that while video is not required in the specs, skipping it hands creative control for video placements to auto-generation unless you both upload your own orientations and adjust the campaign setting. For brands that care about how they appear on video inventory, Google’s documented path is to supply all 3 orientations yourself. [8][9][10]

Ad Strength ratings and what Excellent requires

Google defines Performance Max Ad Strength ratings as a scale with 5 levels: Incomplete, Poor, Average, Good, and Excellent. Incomplete indicates that the asset group is below the minimum needed to serve, while Poor corresponds to only the minimum required assets being present. Average reflects that all asset types are present but with limited variety, and Good indicates all types with better variety and text diversification. [12]

Excellent Ad Strength, per Google’s documentation, requires that you add optional asset types and fully use the available text slots. Specifically, Excellent requires at least 6 sitelinks, your own uploaded videos in all 3 orientations, and full text diversification using all 15 headline slots and all 5 description slots. [13]

Google reports that advertisers who improve Performance Max Ad Strength from Poor to Excellent see about 6% more conversions on average, based on its internal data. This figure is an aggregate outcome and not a guaranteed lift for any specific account, and Ad Strength is not a compliance score to maximize at any cost. It measures coverage and variety, so repeating near identical text across all slots can technically fill them without delivering the diversity that the rating is designed to capture. [12][13][14]

Structuring asset groups and Temper And Forge’s asset standards

Google’s best practices state that you should organize asset groups around a specific theme or target audience, such as product or service lines. This means structuring groups so that each one has coherent creative and landing pages for a defined set of offerings, rather than using a single asset group for all products. Text customization at the campaign level can generate additional headlines and descriptions from your landing page content, domain, and current ads, but the base structure still follows theme or audience groupings. [15]

Feed only Performance Max configurations are possible for retail when you rely solely on Merchant Center data, but once you add manual assets to an asset group, you cannot delete them to revert to a pure feed state. That constraint should factor into how you plan your asset group structure and when you introduce additional creative beyond the feed. [2]

Temper And Forge’s stated practice is that assets are the whole game in Performance Max, and the firm’s preference for the campaign type is explicitly asset contingent. If a client has strong video, or Temper And Forge can help build solid video and visual content, Performance Max is generally the most successful path, because video performs well across Google’s syndication and visual interaction is decisive on shopping. In practice, Temper And Forge never lets the system auto-generate video for a brand that cares how it looks, treats the Excellent checklist as a floor for coverage rather than a goal in itself, and reads asset level performance directionally across channels with ROAS as the final decision metric.