Set up Performance Max experiments in the Experiments page

An illustration that depicts Performance Max experiments in Google Ads campaigns.

Performance Max Experiments are experimentation tools in Google Ads that help you A/B test different features, settings, and campaigns to improve results for your business. You can use experiments to help you measure the incremental lift of using Performance Max campaigns.

How it works

A control and trial group is created for each experiment such that Performance Max displays ads only to viewers in the trial group alongside your other campaigns, and not to viewers in the control group. This means that the Performance Max campaign will only run on 50% of eligible traffic during the experiment.

Review the below terminologies:

  • User selects: This is the Performance Max campaign that you want to measure uplift for.
  • Automatically selected: This is a group of comparable campaigns from the same account (the list of campaigns can be edited post experiment set up).
  • Traffic split: It’s 50% by default for all campaigns included in the experiment.
  • Control group: It’s a group of existing comparable campaigns in the account at 50% traffic (Performance Max traffic is suppressed or zero for advertisers in this group).
  • Trial group: It’s a group of existing comparable campaigns in the account at 50% traffic, and the selected Performance Max campaign at 50% traffic.


Note: The instructions below are part of a new Google Ads user experience that will launch for all advertisers in 2024. If you’re still using the previous version of Google Ads, review the Quick reference map or use the Search bar in the top navigation panel of Google Ads to find the page you’re searching for.

Setup Uplift experiments for Performance Max

Performance Max Uplift experiments help you measure the uplift or incremental benefit of using Performance Max alongside your existing Search, Video, Discovery, and Display campaigns.
  1. In your Google Ads account, click the Campaigns icon Campaigns Icon.
  2. Click the Campaigns drop down in the section menu.
  3. Click Experiments.
  4. Click Performance Max campaign experiments.
  5. To create a new experiment, click the plus button , and then click + Test uplift from Performance Max.
  6. Click Select campaign to select an existing Performance Max campaign for the experiment. If you want to create a new campaign for your experiment, click Create new.
  7. Click Confirm.
    • In the “Performance Max (treatment)” section, your selected campaign will be tested against an automatically selected list of comparable campaigns. You can update this list in the future.
  8. From the “Traffic split” section, select the traffic split percentage as “Treatment group” and “Control group”.
  9. Click Next.
  10. View which campaigns are in each experiment arm in the “Test groups” section.
  11. To rename your campaign, click on the “Experiment name” field.
  12. Click the “Start date” drop-down to select the start date.
  13. Click Schedule.
It’ll take one day after the experiment starts to populate the list of comparable campaigns that were automatically chosen for the experiment. After the list is populated, you’ll get an option to edit the comparable campaign list, and add or remove any campaigns from your experiment. You can make these changes for up to 7 days from your experiment’s start date.

Setup regular shopping campaign vs. Performance Max experiments

  1. In your Google Ads account, click the Campaigns icon Campaigns Icon.
  2. Click the Campaigns drop down in the section menu.
  3. Click Experiments.
  4. Click Performance Max campaign experiments.
  5. To create a new experiment, click the plus button , and then click + Test vs. Shopping campaign.
  6. Click Select campaign to add an existing Performance Max campaign for the experiment. Note that you can test only one Shopping campaign against Performance Max. Click the pencil icon Edit to reselect your campaign.
  7. From the “Traffic split” section, select the traffic split percentage as “Treatment group” and “Control group”.
  8. Click Next.
  9. View which campaigns are in each experiment arm in the “Test groups” section.
  10. To rename your campaign, click on the “Experiment name” field.
  11. Click the “Start date” drop-down to select the start date.
  12. Click Schedule.
  13. Click Create new if you would like Google to automatically create a Performance Max campaign to test against with the same exact settings or targeting.
  14. If you already have a Performance Max campaign that you wanted to test with, click Select campaign.
    • Select a required campaign, then click Next.
    • A default name will appear in “Experiment name”.
    • Select a start date, then click Schedule.

Create a new Performance Max campaign

  1. In your Google Ads account, click the ;Campaigns icon Campaigns Icon.
  2. Click the Campaigns drop down in the section menu.
  3. Click Campaigns.
  4. Click the plus button to create a new campaign.
  5. Select your campaign objective.
  6. Review your conversion goals and if required, remove goals by clicking on the 3-dot icon. If you want to add more goals, click Add goal.
  7. In the “What are you advertising?” section, make one of the following choices:
    • Hotels: Select the hotel you want to advertise.
    • Something else: Add feed label and country of sale by clicking the respective fields. Note that the feed label will replace the selected country of sale. Alternatively, if you don’t want to use a feed label, select a country of sale.
  8. Add your campaign name and click Continue.
  9. A recommended budget populates in the “Bidding” section based on the standard Shopping campaign's budget and the traffic split percentage chosen.
  10. Select whether you want to optimize “Performance Max towards Conversion value or Conversions.
  11. Set an optional target return on ad spend (uncheck the box above if you don’t want to set a target return on ad spend).
  12. In “Locations”, select a target location.
  13. In “Languages”, you can select specific languages or simply click All languages.
  14. Set “Final URL expansion”. It’s recommended to keep “Final URL expansion” on to view maximum performance benefits from your Performance Max campaign.
  15. Now, select a start date and the end date is automatically set to 3 months from the selected start date.
  16. Click More settings to adjust “Ad schedule” and “Campaign URL options”.
  17. Click Next to set up your asset group.
  18. Add asset group name, assets, and audience signal.
  19. Click Next.
  20. Set any required extensions by setting up “Call extensions”, “Load form extension”, and “Sitelink extensions”.
  21. Click Next.
  22. Now review the summary of your experiment and click Publish campaign when ready.
  23. After publishing your campaign, you’ll be taken back to the page where you set up the experiment.
  24. Now, scroll down and click Next.
  25. Review your experiment settings again then click Schedule.

Frequently asked questions

Experiment settings

Will existing campaigns be impacted by running the experiment?

Performance for existing campaigns won’t be negatively impacted by experiments. Putting them into base and trial simply tags which ones had Performance Max traffic alongside them and which ones didn’t. For the existing campaign traffic in the trial arm, Google will measure what happens when it runs alongside Performance Max. This should capture any effects of traffic shifting as well.

Make sure to target the same products in both the regular Shopping campaign, and the Performance Max campaign in order to accurately test the performance of both campaigns. Furthermore, please ensure that the products targeted in the 2 campaigns aren't targeted by any other campaigns outside of the experiment. This will help ensure that the experiment won't interfere with existing campaigns in the account.

Can I change the traffic split between base and trial?

Traffic split options are available for Shopping versus Performance Max campaigns, but unavailable for non-GMC (Google Merchant Center) Uplift Experiments.

Can Performance Max experiments run alongside other ongoing experiments in the account (for example, Ad Variations, Drafts, and Experiments)?

Yes, it’s technically possible to run other types of experiments in the same account. However, it's recommended you minimize these if possible.

Can I change the budgets for my Performance Max or comparable campaigns while an experiment is running?

Yes, you can. However, it’s generally recommended to make as few changes as possible while an experiment is in progress.

Do changes to the base arm affect the experiment arm?

Yes, you can make changes to campaigns, then Google will automatically pick them for comparable campaigns and apply them to base and trial. However, making changes while an experiment runs isn't recommended.

Are comparable campaigns expected to change throughout the experiment?

This can be expected if changes are made to the campaign that are around conversion goal, domain, or location. If campaigns are added or removed, or the above changes are made in existing campaigns, additional comparable campaigns can be added or removed.

In the child accounts “Labs” tab, the Uplift Experiments feature is visible for a user who directly logins to the child account but isn’t shown for a user drilling down from an MCC to the child account. Is the Performance Max Uplift Experiment feature available for MCC users?

If an MCC user wants to access the tool, they must allowlist the MCC. If not, they'll only be able to access it on the child account level. View example.

What’s the effect on my existing campaigns when they’re part of an experiment?

Existing campaign settings aren’t affected by being in the experiment. Keep in mind:

  • Any existing Performance Max campaign that’s part of an experiment may notice a decrease in traffic because the campaign will only serve to 50% of the eligible traffic. When the experiment ends, Performance Max traffic should recover to pre-experiment levels if you launch the performance Max campaign.
  • Any new Performance Max campaign created as part of this experiment will notice an increase in traffic if it’s launched to 100%.

How much budget should I use for Performance Max campaigns?

The higher your Performance Max budget and spend is compared to the total spend in your account, the higher your chances are of noticing statistically significant results.

Should I double my Performance Max campaign budget since it’ll only serve on 50% of the eligible traffic?

Set a budget you’re comfortable spending for the experiment despite the traffic suppression. Even if ads serve to only 50% of the eligible traffic, you might end up using the entire budget. Remember, your budget can be doubled (the daily limit) similar to standalone campaigns.

How and when does the user split happen between the two arms?

A user split occurs at the start of the experiment and Google’s systems try to ensure fairly balanced arms. While the experiment isn’t limited to only signed-in users, signed-in users make it easier for a clean split. For signed-out users, there aren’t guarantees provided, but the distribution should be similar in both arms.

Technical considerations

Are Uplift experiments available for all MOs?

Uplift experiments are currently only available to advertisers using the Online Sales (Non-feed), Store goals (Offline) and Lead Gen MOs. Uplift experiments don't support Performance Max with GMC feed.

Will Uplift experiments work with Performance Max when it has SA360 Floodlight support?

The Uplift experiments tool is currently only available in Google Ads. Advertisers need to create, manage, and view summary reporting on experiments in the Google Ads interface.

Experiment results

My Experiment status shows results are inconclusive. How long does it take to get conclusive results?

It’s recommend that you run the experiment for at least 4-6 weeks.

Why don’t my Experiment results seem to include the first 7 days of data?

It’s recommend experiments run for at least 4-6 weeks, and the first 7 days of data is discarded to account for the experiment ramp-up time. This ensures that you’re evaluating both arms fairly. For example, if your experiment start date is December 1 and the end date is December 31, you’ll only view data for the period between December 8-31 in the Experiment results page. However, you should be able to view stats for all campaigns in the main campaigns table for your desired date range.

Am I able to view how many conversions or how much conversion value my comparable campaigns drove in the trial arm?

No. You’ll only be able to view aggregated conversions, conversion value, CPA, ROAS, and spend for the groups. The goal of the experiment is to show you how much more conversions or conversion value the Performance Max campaign is driving for the account as a whole.

Here are best practices for responding to experiment results:

Experiment results Conclusion and recommendations
The trial arm drove more conversions or conv value at the same or better CPA or ROAS compared to control arm.

Running Performance Max alongside comparable campaigns can bring you additional conversions at a comparable ROI.

Recommendation: Launch the Performance Max campaign and scale budgets to get more coverage and efficient conversions at that ROI.

The trial arm drove more conversions or conv value at a CPA or ROAS worse than the control arm.

If the Performance Max campaign had a target CPA or ROAS set, evaluate if they are comparable to targets for other performance campaigns.

  • If targets aren’t comparable, then the test should be adjusted. Performance Max automation will always try to achieve the set CPA or ROAS targets within the available budget.
    • Recommendation: Continue testing after adjusting CPA or ROAS targets.
  • If targets are comparable, then this result could be because Performance Max was driving additional conversions, which may have used additional budget.
    • Recommendation: Continue to run Performance Max campaigns as part of overall cross-channel strategy.

If the Performance Max campaign didn’t have a target CPA or ROAS set but comparable campaigns did, performance for the trial arm can seem worse.

  • Recommendation: Re-run the experiment with a target set (you can start with the account average CPA or ROAS).

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