Google Ads Update: You Can Now Cap How Much PMax Spends on the Display Channel

Google Ads is rolling out a fix for one of Performance Max's longest-standing frustrations: you can now cap how much of your PMax budget flows to the Display channel. It works through a new priority setting, high or low, applied per channel, with an option to set a capped percentage of budget. The catch is that every channel defaults to high priority, so if you do nothing, nothing changes.

This is a big deal for anyone who has watched a PMax campaign quietly tip a huge share of spend into Display placements that never seem to convert. Here's what the update actually means, why Display overspend happens in the first place, and how to use the new controls (plus the older workarounds) to keep your campaign mix sensible.

What Is PMax Display Capping?

Display capping is Google's new mechanism for limiting how much budget Performance Max allocates to the Display network. Instead of the algorithm deciding unchecked, you now mark each channel (Search, Display, YouTube, Shopping, etc.) as high or low priority.

Here's how the system behaves:

• Google funds high-priority channels first.

• Low-priority channels only get a capped percentage of your total budget.

• Every channel starts on high priority by default, so you need to actively change the setting for anything to happen.

This matters because, until now, advertisers had no direct lever to say "spend less on Display" inside a PMax campaign. You could influence it indirectly, but never cap it outright.

How Performance Max Allocates Budget Across Channels

PMax pools your budget across Search, Display, YouTube, Discover, Gmail, Maps and Shopping inventory, then lets its bidding algorithm decide where to spend based on predicted conversion value. There's no manual bid adjustment per channel in the way a classic Display campaign allows. The algorithm is chasing the best overall return, not necessarily the best return per channel.

Why "Display Capping" Isn't a Native Standalone Feature, It's a Use of the Priority Tier

It's worth being precise here: Google hasn't built a dedicated "Display budget cap" slider. What it has built is a priority tier system, and Display capping is simply what happens when you apply a low priority and a capped percentage specifically to the Display channel. It's a general-purpose channel control that advertisers are now using to solve the Display overspend problem specifically. You can apply the same logic to any other channel within PMAx.

Common Scenarios Where Display Spend Gets Out of Control

A few patterns show up again and again in PMax accounts that we audit:

• A campaign with broad asset groups and wide final URL expansion starts pulling huge impression volumes from Display placements with low relevance.

• Seasonal or promotional campaigns see Display spend spike because the algorithm is hunting for volume to hit a target ROAS, and Display inventory is cheap and plentiful.

• Brand-new campaigns with limited conversion history lean on Display more heavily while the algorithm is still learning.

Why Display Overspend Happens in Performance Max

At its core, Display overspend happens because PMax is built to chase conversion value across every channel it has access to, not to respect an advertiser's channel preferences. A few specific factors compound the problem.

Lack of Channel-Level Bid Controls

Until this update, there was no way to tell PMax "bid less aggressively on Display inventory." The algorithm treated every available placement as fair game provided it predicted a reasonable chance of conversion.

Low-Quality or Irrelevant Placements

Display inventory varies enormously in quality. Some placements genuinely drive sales; others are low-value apps or websites where clicks are cheap but rarely convert. Without exclusions, PMax will happily buy a lot of the latter if the algorithm's model says it's worth the punt.

Asset Group and Audience Signal Issues

Weak or overly broad audience signals give the algorithm less to work with, which can push it towards reach-based channels like Display rather than higher-intent channels like Search. If your asset groups lack strong creative tailored for Display placements, performance on that channel tends to suffer further.

How the Google Ads Algorithm Prioritises Reach vs Conversion Value

PMax is ultimately optimising for your stated goal, usually conversions or conversion value, within your target CPA or ROAS. Display can look attractive to the algorithm because it's cheap and scalable, even if the actual conversion quality lags behind Search or Shopping. That's the central tension advertisers have been fighting since PMax launched.

How to Identify If Display Is Hurting Your PMax Performance

Before you cap anything, confirm Display is actually the problem. Capping a channel that's quietly performing well will cost you conversions.

Using the Placements Report (Insights Tab)

Google Ads provides a placements view inside PMax reporting (via the Insights tab) that shows where your Display impressions are landing. Review it regularly for irrelevant or low-quality sites and apps.

Checking Channel-Level Performance via Scripts or Third-Party Tools

Because PMax doesn't break out channel performance as cleanly as legacy campaign types, many advertisers lean on Google Ads scripts for PPC automation or third-party reporting tools to pull a clearer channel-by-channel breakdown and flag anomalies automatically.

Key Metrics to Watch (CTR, Conversion Rate, CPA by Channel)

When you do get channel-level visibility, compare:

• Click-through rate by channel, low Display CTR against a healthy Search CTR is a red flag.

• Conversion rate by channel, Display typically converts lower than Search, but a very large gap suggests waste.

• Cost per acquisition by channel, if Display CPA is well above your target while consuming a disproportionate share of budget, that's your signal to act.

Methods to Limit or "Cap" Display Spend in PMax

With the new priority setting live, capping Display is now your first and most direct lever. But it works best alongside the older tactical controls advertisers have relied on for years.

Using the New Priority Setting

Set Display to low priority and choose a capped percentage of your budget. Start conservatively, a smaller cap, and monitor overall campaign performance before tightening further. Remember that search and other high-priority channels will always be funded first under this model.

Placement Exclusions (Account and Campaign Level)

You can exclude specific websites, apps, YouTube channels and videos from receiving your ads, either at account level (affecting every campaign) or campaign level. This is still one of the fastest ways to cut off obviously poor-quality Display inventory. Our guide on how to exclude placements in Google Ads walks through the process in more detail.

Using Negative Keywords and Content Exclusions

Content exclusions let you avoid certain types of content (like live-streamed content, embedded video, or specific content labels) that tend to correlate with lower-quality placements. Negative keywords work differently in PMax than in Search campaigns, so it's worth confirming how they're currently supported before relying on them heavily.

Brand Safety and Inventory Exclusion Lists

If brand safety is a concern alongside wasted spend, apply inventory exclusion lists to prevent your ads appearing next to sensitive or inappropriate content. This protects your brand while also, often, improving overall placement quality.

Restructuring Asset Groups to Reduce Display Eligibility

Tighter, more specific asset groups with strong audience signals give the algorithm clearer direction, which can reduce its reliance on broad Display reach to fill its goals. For a deeper look at this, see our asset group optimisation tips.

Leveraging Final URL Expansion Settings

Final URL expansion lets Google send traffic to pages beyond the ones in your asset group. Switching this off, or tightening it, keeps traffic (including Display-sourced traffic) landing where you intend, which often improves conversion quality.

Using Scripts to Monitor and Alert on Display Spend Spikes

Even with capping in place, it pays to monitor for spikes. A simple script that checks channel spend daily and alerts you if Display crosses a set threshold means you catch problems before they burn through budget.

Workarounds and Advanced Strategies

Capping solves the core problem, but a few complementary strategies are still worth considering.

Running Separate Search and Display Campaigns Alongside PMax

Some advertisers prefer running a dedicated Display or Search campaign outside PMax for full manual control, while letting PMax handle the rest. This trades some automation efficiency for precision, and it's a trade-off worth weighing carefully. Our comparison on Search vs Display vs PMax: choosing the right campaign type covers when each structure makes sense.

Using Performance Max Channel Priority Settings as They Expand

As this rollout matures, expect Google to refine how priority and capping apply across other channels too, not just Display. Keep an eye on your Google Ads release notes and test new controls as they appear in your account.

Feedback Loops: Reporting Placement Issues to Google

If you consistently see poor-quality placements that exclusions don't catch, report them to Google through the in-platform feedback tools. It won't fix things overnight, but it does feed into the inventory quality signals Google uses over time.

Best Practices for Managing Channel Mix in Performance Max

Setting Realistic Expectations for Automated Campaigns

PMax is built for automation, not granular manual control. Even with capping now available, you're still working within an algorithm-driven system. Expect to monitor and adjust, not set-and-forget.

Testing and Iterating on Asset Groups

Treat your asset groups as a living part of the campaign. Refresh creative, tighten audience signals, and review performance regularly rather than leaving a campaign to run untouched for months.

When to Escalate to Your Google Ads Rep

If you've applied capping, tightened exclusions, and restructured asset groups, but Display spend or quality issues persist, it's worth raising the specific placements and data with your Google Ads account team. They can sometimes flag inventory issues that aren't visible or actionable from the advertiser side.

If managing all of this feels like more than your team has time for, it's exactly the kind of ongoing optimisation our Google Ads specialists handle day to day for clients running PMax at scale.

Frequently Asked Questions

Does the new PMax display capping feature cost extra or require a special setting to access?

No, it's a rollout within standard Performance Max campaign settings. You simply need to locate the channel priority controls in your campaign and adjust them, there's no additional cost or separate product to enable.

Will capping Display hurt my overall PMax performance?

It can if Display was genuinely contributing conversions. Check your placement and channel performance data first, cap gradually, and monitor your overall CPA or ROAS after making changes rather than switching Display off entirely from day one.

Can I cap other channels besides Display in Performance Max?

The priority and capping system applies to channels generally, not just Display, so you can apply the same high or low priority logic to other channels like YouTube if they're causing similar overspend issues.