Performance Max is Google’s most automated campaign type. A single campaign runs across every Google channel simultaneously — Search, Display, YouTube, Gmail, Maps, and Discover — and Google’s AI decides where to show your ads, who to show them to, and how much to bid. For advertisers used to controlling keywords and placements, this level of automation can feel uncomfortable. But when set up correctly, Performance Max consistently generates incremental conversions that Search campaigns alone cannot capture.
This guide covers exactly how Performance Max works, how to set it up, what you need to make it succeed, and how to avoid the mistakes that cause most campaigns to underperform.
How Performance Max Works
Performance Max uses Google’s Smart Bidding and machine learning to serve ads across all of Google’s inventory from a single campaign. You provide the raw materials — creative assets, audience signals, and a conversion goal — and Google’s algorithm figures out the best combination of channel, audience, creative, and bid to achieve that goal.
The key distinction from traditional campaigns is that Performance Max does not operate on keywords. Instead of targeting specific search queries, you provide audience signals that tell Google who your ideal customer is. Google uses those signals as a starting point, then expands to find additional audiences it predicts will convert.
Performance Max is optimised for conversions or conversion value. It requires conversion tracking to function, and it performs significantly better when conversion volume is healthy — Google recommends at least 50 conversions per month across your Google Ads account before launching Performance Max.
Asset Groups: The Building Blocks of Performance Max
The core structure of a Performance Max campaign is the asset group. An asset group is a collection of creative assets — headlines, descriptions, images, logos, and videos — that Google assembles into ads dynamically depending on where the ad is being shown. A single Performance Max campaign can contain multiple asset groups, and each asset group can be themed around a different product, service, or audience segment.
The creative requirements for each asset group are:
- Headlines: Up to 15, each up to 30 characters. Provide as many as possible for maximum ad variation.
- Long headlines: Up to 5, each up to 90 characters.
- Descriptions: Up to 5, each up to 90 characters. One description can be up to 60 characters.
- Images: Multiple formats required. Landscape (1.91:1 ratio), square (1:1), and portrait (4:5) images. Provide at least 3 to 5 images per format.
- Logo: Square and landscape logo formats.
- Videos: Optional but strongly recommended. Horizontal (16:9), vertical (9:16), and square (1:1) formats. If you do not provide videos, Google will auto-generate them from your images and text — and auto-generated videos are almost always lower quality than what you would create yourself.
- Sitelinks and callouts: These carry over from your account-level or campaign-level extensions.
Asset groups with high-quality, diverse creative inputs consistently outperform those with minimal assets. Use the full 15 headlines and 5 descriptions. Provide multiple image formats. Upload your own videos.
Audience Signals: Guiding the Algorithm
Audience signals are not targeting in the traditional sense — Performance Max will show ads beyond your specified signals if it predicts conversions elsewhere. Think of audience signals as suggestions that give the algorithm a head start, not hard constraints.
The most valuable audience signals to provide are:
- Customer lists: Upload your existing customer database. This is the strongest signal you can give Google — it shows the algorithm exactly who your customers are.
- Website visitors: Remarketing lists from Google Ads or GA4 audiences, especially people who reached high-intent pages like pricing or checkout.
- Custom intent audiences: People who have searched for specific keywords related to your business. Define these based on your best-performing keywords from Search campaigns.
- In-market and interest audiences: Use Google’s predefined audiences that match your customer profile as supplementary signals.
The more specific and high-quality your audience signals, the faster Performance Max learns. Accounts with customer lists consistently see shorter learning periods and stronger early performance.
How to Set Up a Performance Max Campaign
Setting up Performance Max takes more preparation than a standard Search campaign. Do not rush the asset creation phase — the quality of your inputs directly determines the quality of your outputs.
Step 1: Define your conversion goal. Performance Max optimises for a specific conversion action. Make sure your most important conversion — purchase, lead form submission, phone call — is tracked accurately before you launch. Optimising for a proxy event (like page views) will generate traffic, not customers.
Step 2: Set your budget and bidding. Start with Maximize Conversions and switch to Target CPA or Target ROAS once you have stable performance data. Your initial daily budget should be at least three to five times your target CPA to give the algorithm room to learn. If your target CPA is £100, start with at least a £300–£500 daily budget.
Step 3: Configure URL expansion. Performance Max can automatically test different landing pages on your site. If you have a well-optimised landing page, consider limiting URL expansion to that page. If your site has multiple relevant pages, broader URL expansion can be beneficial.
Step 4: Build your asset groups. Create separate asset groups for different products, services, or audiences. Use all available headline and description slots. Write copy that speaks to specific customer pain points and calls to action. Upload all image formats. Provide your own videos if at all possible.
Step 5: Add audience signals. Upload customer lists and add remarketing audiences. Define custom intent audiences based on your best-performing keywords. The more relevant your signals, the faster the algorithm learns.
Step 6: Add brand exclusions. Exclude your own brand terms to prevent Performance Max from cannibalising your branded Search campaigns. Brand exclusions can be requested through your Google rep or via the campaign settings.
Optimising a Performance Max Campaign
Performance Max’s automation does not mean set-and-forget. The algorithm makes the bidding decisions, but you are responsible for the inputs and the strategic direction.
Monitor asset performance ratings. In the Assets section of your campaign, Google rates each asset as Low, Good, or Best. Replace Low-performing assets regularly. Test new headlines, descriptions, and images every four to six weeks.
Review the search terms insight report. Performance Max does not show full keyword-level data, but the Insights section shows search categories and themes driving conversions. Use this to understand where the algorithm is finding success and inform your Search campaign keyword strategy.
Check audience insights. The Audience insights panel shows which audience segments are performing best within Performance Max. This is useful for informing your broader marketing strategy and understanding who is actually converting.
Use campaign-level negative keywords carefully. Performance Max supports negative keywords at the campaign level, but adding too many can constrain the algorithm’s ability to find conversions. Only add negatives that are clearly irrelevant to your business.
Give it time. Performance Max requires a learning period of four to six weeks before you can accurately evaluate performance. The algorithm needs sufficient conversion data to optimise effectively. Do not make significant changes in the first month and do not judge results in the first two weeks.
Performance Max vs Search Campaigns
Performance Max and Search campaigns are not competitors — they are complements. Search campaigns give you precise control over high-intent keywords and are essential for capturing users who are actively searching for what you sell. Performance Max reaches users across multiple channels and finds conversions through audience signals and creative performance rather than keyword targeting.
The best account structure for most businesses is running both simultaneously. Use Search campaigns for your core commercial keywords with tight match types and strong negative keyword lists. Run Performance Max alongside to capture incremental conversions from YouTube, Display, Discover, and broader Search inventory that your Search campaigns are not covering. Set your Search campaigns to maximise impression share on brand terms and exclude those brand terms from Performance Max to prevent overlap.
Common Performance Max Mistakes
Launching without conversion data. Performance Max requires conversions to optimise. Launching with no conversion history sends the algorithm in blind. Build at least 30 to 50 conversions per month in your account before introducing Performance Max.
Using only a few assets. Providing the minimum number of headlines and a single image format severely limits what the algorithm can test. Give it more material to work with.
Not providing videos. If you skip videos, Google auto-generates them from your images and text. These auto-generated videos tend to perform poorly. Invest in even simple, phone-shot video content — a 15-second direct-response video outperforms a Google-generated slideshow every time.
Setting the Target CPA too low too early. If your target is too aggressive, Performance Max will under-deliver and miss auctions to protect your CPA. Start at or above your current average CPA and tighten it gradually once the campaign has stabilised.
Not excluding branded search terms. Without brand exclusions, Performance Max will bid on your own brand name and inflate your impression share on branded queries — which your brand Search campaign was already capturing. This makes Performance Max look better than it is while providing no incremental value.
Not sure what good performance looks like? Check our ROAS benchmarks by industry to see how your campaigns compare.
Frequently Asked Questions
Is Performance Max better than Search campaigns?
Performance Max and Search campaigns serve different purposes. Search campaigns give you precise control over keywords, bids, and ad copy, making them ideal for capturing high-intent searches. Performance Max runs across all Google inventory (YouTube, Display, Gmail, Maps, Discover, and Search) and uses AI to find conversions wherever they exist. For most accounts, the best approach is running both: Search campaigns for your core high-intent keywords and Performance Max for incremental reach. Performance Max should complement, not replace, your Search campaigns.
How much budget does a Performance Max campaign need?
Google recommends a daily budget of at least 3 to 5 times your target CPA to give the algorithm enough room to optimise. In practice, Performance Max campaigns need a minimum of $50 to $100 per day to generate enough data for the algorithm to function. Below that threshold, the campaign will struggle to exit the learning phase and performance will be inconsistent. Scale budget gradually once the campaign has demonstrated consistent CPA performance over two to four weeks.
How long does Performance Max take to optimise?
Performance Max has a formal learning period of approximately six weeks. During this time, the algorithm is testing asset combinations, exploring audience signals, and calibrating its bidding models. Performance in the first two to three weeks is often volatile. Evaluate results after a full six-week learning period before making strategic decisions or adjusting targets significantly.
Can I see what keywords Performance Max is targeting?
Not directly. Performance Max does not expose keyword-level data the way Search campaigns do. You can view search themes and categories in the Insights section, and you can see which asset combinations are performing best in the Assets report. For more granular search query visibility, you need to cross-reference with your Search campaigns and use the search terms report there. This lack of transparency is one of the main criticisms of Performance Max from experienced advertisers.
Should I run Performance Max for lead generation or only for ecommerce?
Performance Max works for both lead generation and ecommerce, but the setup differs. For ecommerce, connect your Google Merchant Center feed to Performance Max to enable Shopping inventory and dynamic product ads. For lead generation, focus on high-quality audience signals, tight landing pages, and clear conversion actions. Lead generation Performance Max campaigns tend to benefit most from strong remarketing lists and customer match data as audience signals.
