Google changes Smart Bidding on Aug 17: What you need to do

Do you have a campaign delivering a lower cost per conversion than you actually requested? A campaign where you set a target CPA of DKK 100, but in practice land at DKK 65? Then there is a good chance Google will alter that quiet gain in a few days – without asking you first.

On August 17, 2026, Google is adjusting how Smart Bidding behaves in budget-constrained campaigns. It sounds technical, but the consequence is very concrete for your ad account. Let’s unpack it.

What is changing?

Today, a campaign using Target CPA or Target ROAS that is marked “Limited by budget” can actually overperform relative to its target. Google has had room to hunt for cheap conversions, and the result for many advertisers has been a CPA or ROAS that was noticeably better than the figure they typed in themselves.

Starting August 17th, bids will be optimized “more consistently toward your target when the campaign has a limited budget,” as Google phrases it. In other words: instead of beating your target, the algorithm optimizes closer to the exact number you entered. That leeway to find extra efficient conversions is being tightened.

The change applies to Target CPA and Target ROAS across Search, Shopping, Performance Max, Demand Gen, and Travel. Campaigns that are NOT limited by budget will see no change in behavior.

An important point: Google does not automatically adjust your budgets or targets for you. The responsibility to act lies with you.

Why does this matter to you?

Because the “free” efficiency you might not even have noticed could vanish. If one of your campaigns has been delivering a CPA below target, Smart Bidding has effectively done discovery work on your behalf – finding pockets of cheap conversions that competitors overlooked. After August 17th, that work will increasingly be something you have to manage yourself through your targets.

This isn’t necessarily bad news. Google made this change to make performance more predictable, especially when adjusting budgets. For some advertisers, it has been frustrating that a campaign behaved differently than its target suggested. Now, the relationship between “the number I ask for” and “the number I get” will be closer.

However, it requires you to know your actual numbers; otherwise, you risk either paying more per conversion than necessary or slowing down a campaign that could have scaled.

How to get started

You still have time to prepare. Take these steps before August 17th:

1. Find the exposed campaigns:

Filter for campaigns marked “Limited by budget” AND using Target CPA or Target ROAS. Those are the ones affected by the change. You can safely leave the rest alone.

2. Look at whether they are overperforming:

Is the campaign delivering a lower CPA (or higher ROAS) than your set target? Then you need to decide: Do you want to lower the target so it matches real performance and maintains efficiency? Or do you want to raise the budget if the economics can support more volume at the current price?

Our take

This isn’t a catastrophe. It’s a reminder to know your numbers. The advertisers who left target setting on autopilot and never looked at whether the campaign beat its target are the ones who will be surprised on August 17th. Those who have control over their actual CPA and ROAS can use this change to clean up and get more predictable performance.

In short: review your account now while you have time to adjust calmly, rather than put out fires later.

If you are unsure which of your campaigns will be affected or how to set your targets after the change, get in touch with us at Iternum Digital. We’d be happy to take a look at your account and help you create a plan tailored to your exact goals. Preparing is far cheaper than guessing.