Short answer: Experiments in Google Ads let you test a change on a share of your traffic while the original campaign keeps running. Create a custom experiment for changes like a new bid strategy, broad match or a different landing page, split traffic about 50/50, run it for at least four weeks or until results are significant, then apply the winner. It is the safest way to try changes that could hurt performance.
Types of experiments
| Type | Use it for |
|---|---|
| Custom experiments | Bidding, keywords, match types, landing pages and settings in Search and Display |
| Ad variations | Testing ad text changes across many ads at once |
| Performance Max experiments | Testing features or measuring uplift for Performance Max |
| Video experiments | Testing YouTube creatives |
Find them under Campaigns, then Experiments.
Good things to test
- Switching from Maximize conversions to Target CPA
- Adding broad match with Smart Bidding
- A new landing page
- AI Max or other automation features
- Different location or audience settings
Test one main change at a time, so you know what caused the result.
How to set up a custom experiment
- Choose the original campaign.
- Make the change in the experiment version.
- Set the traffic split, usually 50%.
- Choose a start and end date. Plan for at least four weeks.
- Pick the success metrics, such as conversions, cost per conversion or conversion value.
How to read results
Google shows the difference between the experiment and the original, with a confidence indicator. Look for:
- A clear difference in your main metric
- Results that are statistically significant
- Stable results across weeks, not one lucky week
If the result is not significant, the change probably made little difference. You can extend the test or try a bigger change.
Apply or end
If the experiment wins, apply the change to the original campaign or convert the experiment into a new campaign. If it loses, end it and keep a note of what you learned.
Common mistakes
- Ending tests after a few days
- Changing the original campaign during the test
- Testing in campaigns with very few conversions
- Testing several changes at once
Frequently asked questions
What are Google Ads experiments?
How long should an experiment run?
What traffic split should I use?
Can I test landing pages with experiments?
What if the result is not significant?
Who can run Google Ads experiments for my account?
Want changes tested properly?
I can plan experiments that answer your biggest questions. See my Google Ads management service or request a free ads audit. Also read How to Test AI Max for Search Safely and Google Ads match types.