Cassidy Abercrombie is Distl’s Senior PPC Specialist. She runs Google Ads for ecommerce and lead-gen clients at the agency, including Australian skincare brand Avocado Zinc, the account she rebuilt for a 42:1 return earlier this year. In this piece she walks through why Google Ads PMax conversion rates are sliding in 2026, what’s behind it, and what the accounts that aren’t sliding are doing differently.
Content Overview
The industry’s been flagging a Google Ads conversion rate slide for months now for PMax campaigns specifically. Across thousands of accounts, benchmark data has conversion rates down close to 9% year on year while click-through rates are up around 7%. So advertisers are getting more clicks, and fewer of those clicks are turning into anything that pays the bills.
Our accounts aren’t sliding the same way. A lot of the job right now is staying ahead of these changes as they roll out, rather than waiting for Google to switch them on automatically. Three changes are doing most of the damage at the moment, and most accounts have them on by default. The rest of the piece walks through each one, and what I do about it.
Conversion rates are down across nearly every industry
The hard numbers first. WordStream and LocaliQ’s 2026 benchmark report shows search conversion rates for PMax campaigns dropped 9.28% year on year across 13 of the 14 industries they track. Click-through rates went up 7.49% across all 14.
If your conversion rate is down by something like 9% year on year and your click-through rate has nudged up, you’re tracking the industry. Nothing’s broken on your end. The question is whether you’re sitting with it or doing something about it. If your numbers are way worse than that, you’ve got something account-specific layered on top of the platform shift, and that’s where to dig.
To put a 9% slide in real terms: a campaign that did 100 conversions a month last year is now doing about 91, before you’ve changed a thing. Multiply that across five active campaigns and you’re losing decent revenue while everyone stares at the dashboard wondering what’s going on.
Two platform changes driving the decline
Three big platform changes are pushing accounts in the same direction at once: less control for the advertiser, more guesswork by Google’s automation. They stack on top of each other. I’ll go through them in the order they’re hitting accounts.
AI Max for Search just went live
AI Max for Search came out of beta on 15 April 2026. It bolts a kind of broad-match-without-keywords targeting onto your Search campaigns and is being positioned as the replacement for Dynamic Search Ads. Google’s own announcement says accounts using the full feature suite see a 7% lift in conversions or conversion value, with some campaigns getting up to 27% growth.
The bit Google doesn’t talk about as much is independent testing across hundreds of accounts shows advertisers are reporting either no improvement or worse results once AI Max is switched on. Whether AI Max helps or hurts seems to depend heavily on how the account is structured, how strong the creative assets are, and whether conversion tracking is firing properly to begin with.
The bigger problem is how it’s getting switched on. Plenty of accounts are getting opted in via “voluntary upgrade” prompts, well before the auto-migration deadline in September 2026. We’ve taken on accounts where AI Max is already running and the marketing manager doesn’t remember turning it on. Someone clicked through a setup prompt three weeks earlier and that was that.
For now, we’re keeping AI Max switched off across the accounts we manage. The early data is too patchy to feel comfortable handing over keyword discovery on accounts where every dollar needs to pull its weight, and we’ll change our position when the data does. If you want to test it on a single campaign in a controlled way, our guide to trialling AI Max walks through how to do it without blowing up the rest of the account.
Performance Max is stealing from Search
According to a large-scale study covered by Search Engine Land, 97% of PMax campaigns overlap with Search campaigns on actual search terms. On those overlapping queries, the Search campaign converts better 84% of the time.
When both campaigns could show an ad for the same query, PMax usually wins the bid, but Search would have done a better job of converting it. PMax’s “search themes” behave more like phrase or broad match than exact match. Higher-intent queries are getting routed into the campaign type that’s not as good at closing them.
Hero-product searches and branded queries that used to convert at the usual ecommerce rate are now landing in PMax instead of in a properly-built Shopping or Search campaign, and dragging the whole account’s conversion rate down with them.
If you’re running PMax alongside Search and you haven’t actively layered in negatives to protect your high-intent queries, PMax is eating your best converters. Exact-match keywords are now the main tool for protecting the queries you actually want to win.
Three smaller things worth checking
These are smaller, but they compound the bigger three above:
The Unfair Advantage policy. Live since April 2025. It lets the same advertiser show up twice on a single search results page across separate ad slots. If you’re a smaller advertiser, that translates to lower impression share and bigger players squeezing you out.
Your Data Exclusions for PMax. Rolled out for Performance Max in Q1 2026, this lets you exclude existing customers and site-visitor lists from PMax targeting. If someone enabled it on your account, conversion volume will have dropped because existing-customer conversions are correctly being removed from the prospecting pool. The feature’s working as intended. The problem is when nobody flags that it’s been switched on, and the volume drop looks like a mystery.
Smart Bidding thresholds matter more than ever. Target CPA needs about 30 conversions a month to bid sensibly. Target ROAS needs about 50. If the industry-wide slide pushes one of your campaigns under that threshold, the algorithm starts making weird decisions on too little data, performance gets worse, and the loop reinforces itself.
Each of these rewards advertisers who know exactly what’s switched on in their account and what isn’t, and punishes accounts running on Google’s defaults. Where to keep the automation and where to keep your hands on the wheel is the key question as Google keeps pushing you to automate everything.
Five questions to ask whoever runs your Google Ads
If you’re a marketing manager overseeing Google Ads in-house or through an agency, these five questions will tell you most of what you need to know about whether your account is in the slide. None of them need a technical answer. The shape of the answer (specific or vague) is the diagnostic.
- Is AI Max switched on for any of our Search campaigns? If yes, why is it on, and did anyone consciously enable it?
- What negatives are protecting our highest-converting queries from PMax? Show me the negative keyword list and the exact-match keywords we use to govern brand and hero-product traffic.
- When did anyone last audit our consent mode setup? Are conversions firing correctly across the consent banner, and have we compared modelled vs measured conversions in the last six months?
- Are any of our campaigns running below the Smart Bidding threshold (about 30 conversions a month for tCPA, 50 for tROAS)? If yes, the bidding is making decisions on too little data and that’s driving the wonkiness.
- Are we optimising bids toward proxy events or actual revenue? If “conversions” includes add-to-cart or thank-you-page-views, that’s why the spend isn’t translating into real money.
If any of those questions get a vague answer, that’s where to start. Most of the ROI work we do starts with cleaning up the bits everyone assumed were already clean.
The platform is genuinely getting harder to run on autopilot. That doesn’t mean the platform’s broken. The accounts winning in 2026 are the ones putting back the controls Google is retiring by default. If you’d like a second pair of eyes on whether your Google Ads account is sliding with the industry or holding its ground, our Google Ads team is happy to run an audit and tell you straight what we’d change first.
Cassidy Abercrombie
Senior PPC Specialist
