Optimizing Performance Max for Online Shops 2026

Performance Max bundles Google advertising surfaces into a single campaign: Google describes the type as access to the entire Google Ads inventory including YouTube, Display, Search, Discover, Gmail and Maps (Google Ads Help). For an online shop this shifts the lever from picking channels to data quality. The market is there: 86% of people aged 16 to 74 in Germany have bought online at least once, 80% search online for information about goods and services (Federal Statistical Office). This guide shows shop operators what Google requires of feed, text, images and video, and which disclosures apply.

What Performance Max is and what matters

Performance Max is the goal-based campaign type in Google Ads. Instead of running a separate campaign per channel, shop operators supply goals, product data and assets; Google decides where ads appear. The help centre states that Performance Max campaigns are goal-based and access the entire Google Ads inventory from a single campaign (Google Ads Help). Anyone who previously steered Shopping, Search and Display separately gives up some controls and gains others: feed, assets and targets.

In daily work this means the product feed in the Google Merchant Center is not a side issue but the foundation. Shopping ads are built from it, and automation draws the match to search queries from its attributes. If a required attribute is missing or an image breaks the rules, Merchant Center disapproves the product. The campaign keeps running, just without that item.

The scale of the market it operates in shows up in official statistics: internet and mail order retail in Germany grew 10.1% in real terms in 2025 compared with the previous year (Federal Statistical Office). For Google Ads in e-commerce that does not automatically mean more budget but cleaner data first: growth goes to sellers whose product data is served at all.

What Google requires of text assets

Text assets are the part of an asset group that Google combines into ads. The requirements are explicit: length and count are documented, and anything that does not fit is truncated or rejected. The table below summarises the minimum an asset group needs.

Two points are regularly missed. First, Google requires at least one headline of no more than 15 characters; it is used in narrow placements. Second, long headlines should exceed 30 characters, otherwise they look truncated on Display surfaces. Filling every field to the maximum length gives up the variance automation needs to build combinations.

The product feed as the foundation

Merchant Center sets firm limits for the central fields: the product title is plain text with at most 150 characters, the description holds at most 5,000 characters (Google Merchant Center). For images, every product image must be at least 500 × 500 pixels; this requirement takes effect on 31 January 2027 (Google Merchant Center). Aligning the feed today avoids a rushed migration later. Since the Merchant API migration there are also new technical paths for the transfer.

A clean data basis starts in the shop system, not in the feed tool. Attributes maintained in the backend, for example in Shopware, can be handed over without an intermediate step. Conversely, replacement rules in the feed rarely repair what is missing from the catalogue. Preparation therefore includes product data maintenance.

Custom labels are particularly useful: Google describes them as a label you assign to a product to organise bidding and reporting in Shopping campaigns (Google Merchant Center). For a shop this means margin, season or stock coverage can be modelled as a segment and run in dedicated asset groups with their own target, for example clearance stock separated from new arrivals. That allows differentiated range control even inside an automated campaign.

Asset groups: images and video

An asset group bundles text, images and video for one theme or range. Google explicitly recommends adding as many assets as possible, up to 15 headlines, 5 descriptions plus images and videos in different orientations (Google Ads Help). Each orientation serves different surfaces; if one is missing, the corresponding placements drop out.

For images the help centre gives a recommended and a minimum size per aspect ratio: landscape 1200 × 628 with a minimum of 600 × 314, square 1200 × 1200 with a minimum of 300 × 300 and portrait 960 × 1200 with a minimum of 480 × 600 (Google Ads Help). Uploads are JPG or PNG with a maximum size of 5 MB. For video, each orientation requires a minimum length of ten seconds.

• At least three headlines of at most 30 characters, including one of at most 15 characters
• At least one long headline of at most 90 characters
• At least two descriptions of at most 90 characters
• Images in three orientations: 1200 × 628, 1200 × 1200 and 960 × 1200
• Square logo 1200 × 1200 and landscape logo 1200 × 300
• At least one video per orientation, each longer than ten seconds

Goals, bidding and data basis

The bidding strategy decides what automation optimises for. For a shop the difference between the number of conversions and their value is decisive: ten orders with a small basket are not the same as three with a high contribution margin. Passing the conversion value makes it available for optimisation; counting a bare event does not.

For optimisation to hold, it needs events in sufficient numbers. A newly created account with a handful of orders per month gives automation few signals; week-to-week variation is then larger than the effect of any setting. In that situation it makes sense to optimise for intermediate steps such as add-to-basket first and switch to purchase later.

Equally important is restraint when making changes. Every change to target, budget or asset group restarts the learning phase. Adjusting weekly ends up measuring your own restlessness rather than the campaign. A fixed rhythm with defined checkpoints and a log of what changed when works better.

Performance Max alongside standard Shopping

Both campaign types can run in one account. Google states the order clearly: search campaigns with an exact-match keyword are served ahead of Performance Max campaigns when a query matches that exact keyword (Google Ads Help). For shop operators this is the basis of any split: whatever should be steered by exact terms belongs in a search campaign.

That produces a division of labour. Standard Shopping and search campaigns carry what keywords and bids can steer. Performance Max takes the surfaces that cannot be addressed that way, that is Display, YouTube, Discover and Gmail, and puts products in front of people who are not searching yet.

How many campaigns an account needs depends on the range, not on a rule of thumb. Too many parallel campaigns fragment the data basis, too few make steering coarse. A workable cut follows the product groups for which you can genuinely own different targets.

Limiting wasted spend

Reduced visibility into search queries is the most common criticism of Performance Max. It cannot be removed entirely, but it can be limited: through exclusions, through the structure of the feed and through which pages qualify as a destination at all.

Three levers work in practice: negative terms at account and campaign level, brand exclusions for third-party brand names and URL exclusions so the campaign does not lead to the legal notice, the privacy page or blog articles. The last point is regularly forgotten and spends budget without any purchase intent.

1. Review search terms: go through the search terms report regularly
2. Set brand exclusions: remove third-party brand names from delivery
3. Maintain URL exclusions: exclude legal notice, privacy, blog and service areas
4. Exclude placements: block conspicuous placements in the Display network
5. Clean the feed: do not transfer products without stock or margin

One frequently overlooked lever is the asset group without its own text and images: it essentially serves Shopping ads from the feed. That limits reach because YouTube and Display drop out, but it makes the campaign easier to steer. For shops on a tight budget it is a possible entry point, not a permanent state.

Conversion tracking and consent

Without reliable measurement every optimisation is blind. For shops that means two things: events have to arrive reliably, and they have to be collected lawfully. The two are connected, because what may not be collected without consent is simply missing from automation.

Section 25 TDDDG governs this in Germany: storing information in an end user terminal device or accessing information already stored there is only permitted if the end user has consented on the basis of clear and comprehensive information (Federal Ministry of Justice). In practice: consent first, measurement second, and tag behaviour coupled to the decision. How this fits with server-side tracking is covered separately.

The second point is the quality of the values. Pass the actual basket value excluding shipping and exclude cancellations where possible. Reporting gross revenue instead optimises for orders that come back later. It is also worth looking at tracking without a consent banner and at your own privacy page.

Mobile surfaces and vertical video

Vertical video is the entry to short formats. Google states a clear requirement: at least one vertical video 10 to 60 seconds long so that Shorts becomes eligible (Google Ads Help). Without that format the campaign stays on the remaining surfaces. That is not a fault, but it should be a deliberate decision.

For the shop itself the mobile path matters next: a click out of a portrait video lands on a page that has to work in the same environment. What that means in practice is set out in our notes on conversion rates in the shop and on mobile checkout.

Mandatory disclosures in ad and feed

Automated delivery changes nothing about the advertiser obligations. Three points affect every Performance Max campaign run by a shop directly.

The third point is not a mere formality: if the feed price differs from the price in the shop, Merchant Center disapproves the product, regardless of the direction of the difference. For short promotions the transfer frequency is therefore decisive, not the price itself.

For changes to asset groups, targets and feed rules the same applies as elsewhere in the shop: anything to be compared needs a clean setup. How to measure changes against each other reliably is covered in our article on data-driven testing; the SEO structure of the landing pages plays its part too.

Step by step to a clean campaign

The order is not arbitrary: without measurement there is no basis, without a feed no inventory, without assets no surface. These eight steps describe the sequence we use in projects.

1. Check measurement: pass the conversion value excluding shipping, steer consent under section 25 TDDDG
2. Clean the feed: titles up to 150 characters, description as plain text, required attributes complete
3. Check images: bring product images to at least 500 × 500 pixels
4. Assign labels: up to five custom labels per product for margin, season and stock
5. Create text assets: 3 to 15 headlines, 1 to 5 long headlines, 2 to 5 descriptions
6. Add image and video assets: one motif per orientation, videos longer than ten seconds
7. Set exclusions: exclude brands, URLs and placements
8. Separate search campaigns: put exact-match keywords into the search campaign deliberately

Frequently asked questions