What is the default duration for an A/B test in Google Ads?

• A. 7 days
• B. 30 days
• C. 14 days
• D. 60 days

Answer: (B)

In Google Ads, the A/B test (experiment) is set to run for 30 days by default. This length helps gather data across a full range of days of the week and varying traffic patterns, producing a more stable, reliable comparison between the control and the variation. You can change the end date if you need a shorter or longer test, but 30 days is chosen because it balances timely insights with adequate data. Shorter durations (like a week or two) may miss weekly cycles and yield noisy results, while longer runs (such as 60 days) can unnecessarily delay decisions without substantially increasing reliability.