About experiment sync

Custom experiments let you propose and test changes to your Search and Display campaigns. Experiment sync ensures that any optimizations you make to your original campaigns while your experiment is running, will be automatically copied to the experiment (trial) campaigns.

This article explains how experiment sync works and how to set it up.

How it works

This manual process of copying changes to experiments can be time-consuming and error-prone, especially if you are running multiple experiments at the same time.

Once your trial starts at the scheduled time, experiment sync will:

  • Automatically update the trial with any changes made to the base campaign since you created the trial.
  • Report all changes in change history.

Note: Experiment sync only works when you make changes in one direction, from base campaign to trial campaign. If you make changes in your trial campaign, those will be ignored.

Keep in Mind

Experiment sync is available for Search and Display campaigns. Any changes made to the trial campaign won’t be synced with the base campaign. Experiment sync is turned on by default when you create a new trial (you will have the option to turn sync off while creating the trial, but can’t change the setting after the trial campaign has been created).

After experiment sync is turned on:

  • It can’t be turned on for trials that have been scheduled or are already running, but it will be available and on by default for new trials.
  • It might require up to 10 minutes after the trial has started to implement the changes.
  • If you have more than one trial scheduled to run (for example 3 trials starting at different times), experiment sync will update all trials with the same updates to ensure that they are aligned with the base campaign.

What happens if an error occurs?

Note: If you make a change in your original campaign, it's best not to make the change in the trial campaign or it may create an error. Experiment sync will automatically make the change to the trial campaign. 

If a sync error occurs during the trial, the system will stop syncing changes for the remainder of the trial. You’ll need to manually sync the base campaign changes to the trial. For example, if you changed the name of an ad group in the base campaign, and the trial campaign already had an ad group with the same name.


  1. Follow the instructions to set up a custom experiment.
  2. In the “Advanced options”, open the “Experiment sync” section. It will be set to On by default.
  3. Click Create experiment. Your trial is completed and ready to run.
Note: If you turn off experiment sync during the creation of the trial, remember to manually update the trial with all base campaign changes that were made after you created the trial.

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