An asset group is the building block inside a Performance Max campaign. It holds a bundle of creative material - headlines, descriptions, images, logos, videos and a landing page address - along with optional hints about the intended audience. Google's own help centre defines it as "a set of creatives that will be used to create an ad depending on the channel it's being served on." The structure exists because Performance Max does not run fixed ads. It assembles a fresh combination for each placement, whether a text ad on Search, a banner on the Display network or a vertical clip in YouTube Shorts. An asset group supplies the raw parts. Microsoft Advertising, which copied the campaign type, uses the same name for the same unit.

What goes inside one

The contents are tightly specified. According to Google's Performance Max specifications, every asset group needs at least three and at most 15 headlines of up to 30 characters, at least one of them 15 characters or shorter. It also needs one to five long headlines and two to five descriptions, both capped at 90 characters, plus a call to action and a final URL. Two display URL paths of 15 characters each are optional.

Images follow a similar pattern. Horizontal images at 1.91:1 (1,200 by 628 pixels recommended, 600 by 314 minimum) and square images at 1:1 are mandatory, and a vertical 4:5 version is optional. Up to 20 images per ratio are allowed, each no larger than 5,120 KB. Video is formally optional. When none is supplied, Google may generate one from the group's other assets.

Alongside creative, an asset group carries signals. Audience signals, such as customer lists or website visitors, tell the system who has converted before without restricting delivery. Search themes, free-text phrases describing what customers search for, act more directly. Google's help page on prioritisation says they "will behave like any phrase or broad match keyword in Search campaigns." The limit, initially 25 per asset group, doubled to 50 in May 2025.

Retail advertisers add a third layer. An asset group linked to a Merchant Center product feed uses listing groups to decide which products it can show, subdividing a catalogue by brand, category or custom label in the way Standard Shopping did.

How the system uses it

Each campaign holds budget, bidding, location and language settings; each asset group holds creative, landing page and signals. Google's API documentation sets a minimum of one asset group per campaign and a maximum of 100, with no sharing between campaigns. Microsoft's developer guide sets the same ceiling of 100, within a limit of 300 Performance Max campaigns per account.

No budget sits at asset group level. Spend is allocated by the campaign, and the system decides which asset group enters a given auction. For search inventory, Google's prioritisation rules apply in order. An identical exact match keyword in a Search campaign wins first. An identical search theme comes next, ahead of a phrase or broad keyword. Where several groups are similarly relevant, "the ad or asset group that generates the ad with the highest Ad Rank will be prioritized." Asset groups without search themes are selected on Ad Rank alone.

The winning group's ad is assembled on the fly, so individual ads have no separate identity in reporting.

Quality is graded through Ad Strength, which for Performance Max runs from Incomplete through Poor, Average and Good to Excellent. According to Google's Ad Strength help page, a Poor group has only the minimum needed to launch and serves to "some available inventories", while an Average group has every asset type needed to reach all of them. An Excellent rating requires optional assets and greater variety.

In the Google Ads API, the unit is split across several resources. AssetGroup holds the name, status, final URLs, Ad Strength and primary status. AssetGroupAsset links each asset to a group under a field type such as HEADLINE or MARKETING_IMAGE. AssetGroupSignal carries audiences and search themes, and AssetGroupListingGroupFilter holds product partitions. A non-retail group and its minimum assets must be created together in a single atomic request; partial failure is not permitted. Retail groups can rely on the feed alone, but adding one optional asset such as a YouTube video without the full minimum set leaves the group in what Google calls "an unsupported state".

On the buy side, advertisers and agencies write the assets and decide how to split groups, typically by product line, audience or language. On the sell side, Google assembles, auctions and publishes.

Origin and evolution

Asset groups arrived with Performance Max. Google opened the campaign type in beta in late 2020, and on November 2, 2021, Eduardo Indacochea, a senior director of product management, announced worldwide availability on Google's blog. The following day, version 9 of the Google Ads API added support for the campaign type, with AssetGroup, listing group filter and signal resources among its tags.

Search themes followed. PPC Land reported their launch on October 28, 2023, with 25 per asset group. Accounts of the early history differ: PPC Land's May 2025 report on the doubled limit says themes first appeared in mid-2022 with a limit of 10, which sits uneasily with its own October 2023 launch report.

The next large change moved material out of the group. Google announced brand guidelines on December 18, 2024. Business names and logos, previously tied to each asset group, moved to campaign level for campaigns with the setting enabled, shifting from the AssetGroupAsset resource to CampaignAsset. The interface rollout for new campaigns was completed on July 14, 2025, and migration of existing ones was expected to finish by October 30, 2025.

Reporting deepened in stages. On September 30, 2025, Irem Erkaya, a senior product manager at Google Ads, added network segmentation to the asset group and asset reports, covering data from June 6, 2025. Version 23 of the API, released on January 27, 2026, made asset group-level channel reporting available - but only through programmatic interfaces, and only for dates from June 1, 2025.

Why it matters to marketers

The asset group is where most of the remaining control in Performance Max lives. Budget and bidding are set once per campaign. Creative, landing pages, product scope and search themes are set per group, which makes the split between groups the main structural decision an advertiser makes. Microsoft extended that control in January 2026, adding asset group-level tracking templates and URL options that had previously existed only at campaign level.

It is also the unit of testing. Asset-level A/B experiments, launched for retail campaigns in October 2024, opened to all Performance Max campaigns in January 2026. Each experiment covers one asset group, splitting traffic between control and treatment assets while untouched "common" assets serve to everyone. The tested group is locked for the duration. At Google Marketing Live on May 20, 2026, Google announced 1-Click Creative Testing inside Asset Studio, folding test creation into the editing flow.

Limitations and disputes

The numbers do not add up, by design. According to Google's asset group reporting page, conversions are not split across the parts of an ad, so asset-level conversions will not sum to the campaign total. Google describes ratio metrics such as cost per acquisition and return on ad spend at asset level as "directional indicators only". The same page discourages removing weaker groups on that evidence alone, arguing that higher-cost groups can still help the campaign reach its goal at the margin.

Control is partial. A group cannot be given its own budget, and spend can concentrate in one or two groups. In an April 2026 discussion covered by PPC Land, agency founder Victor Tomas said the system becomes "less trustworthy" above $100,000 a month, while others reported spend drifting to whatever converted most easily. Some advertisers run feed-only groups with no creative, which in practice confines delivery largely to Shopping.

Google's own documents disagree on basic figures. Its specifications page allows up to 15 videos per group; its asset group best-practice page recommends adding up to "5 videos in different orientations". The experiment help page states that groups with "more than 15 assets" can be maxed out for testing, a threshold that sits awkwardly beside a 15-headline limit.

Not the same as

  • Ad group: the unit in Search, Display, Shopping and Demand Gen campaigns, holding keywords or targeting plus finished ads. Asset groups hold parts, not ads, and have no keywords.
  • Asset set and asset library: an asset set is an API container for feed-like assets such as locations or dynamic items; the asset library is the account-wide store of uploaded images and videos. Neither determines delivery.
  • Listing group: a product partition inside a retail asset group, not a creative container.
  • Audience group: Microsoft's name for the bundle of age, gender and audience lists attached to an asset group as a signal - one per group, according to its developer guide.

Recent developments

Testing is the main area of change. On October 21, 2026, Search Engine Roundtable reported a toggle labelled "Save asset group changes as an A/B test", first shared on LinkedIn by Joey Bidner, which turns ordinary edits into an experiment. Google's help page for the beta says results are applied only when the advertiser chooses. A guide published today by agency Relevant Audience describes an auto-apply box switched on by default.

Developer documentation continues to move. As of October 2026, Google's asset group guide references API version 26, while Microsoft still describes its Performance Max as an open beta worldwide.

Timeline

  • Late 2020 - Performance Max enters beta.
  • November 2, 2021 - Performance Max becomes available worldwide; asset groups become the creative unit.
  • November 3, 2021 - Google Ads API v9 adds Performance Max support.
  • 2022 - Smart Shopping and Local campaigns upgraded to Performance Max.
  • October 28, 2023 - Search themes reported live, up to 25 per asset group.
  • October 2024 - Asset A/B testing launches for retail Performance Max.
  • December 18, 2024 - Brand guidelines announced, moving business name and logos to campaign level.
  • May 2, 2025 - Search theme limit raised to 50 per asset group.
  • June 4, 2025 - Google Ads API v20 adds network, device and conversion action segments to asset group reporting.
  • July 14, 2025 - Brand guidelines rollout completed for new interface campaigns.
  • September 30, 2025 - Network segmentation added to asset group and asset reports.
  • October 30, 2025 - Expected end of brand guidelines migration.
  • January 9, 2026 - Asset A/B testing spotted across all Performance Max campaigns.
  • January 15, 2026 - Microsoft adds asset group-level tracking templates.
  • January 27, 2026 - Google Ads API v23 brings asset group-level channel reporting.
  • May 20, 2026 - 1-Click Creative Testing announced at Google Marketing Live.
  • October 21, 2026 - "Save asset group changes as an A/B test" toggle reported.

Summary

  • Who: Google created asset groups for Performance Max; Microsoft Advertising uses the same structure. Advertisers and agencies build them, and the platforms assemble and serve the ads.
  • What: A container of headlines, descriptions, images, videos, a final URL, audience signals, search themes and, for retail, listing groups, from which ads are generated per placement.
  • When: Introduced with Performance Max general availability on November 2, 2021, and reshaped by search themes (2023), brand guidelines (2024-2025) and A/B testing (2024-2026).
  • Where: Inside Performance Max campaigns, serving across Search, Shopping, YouTube, Display, Discover, Gmail and Maps on Google, and across Microsoft's network on Bing.
  • Why: Performance Max builds ads automatically, so it needs a pool of parts rather than finished ads. The asset group is where advertisers still steer creative, landing pages and product scope.