Search Themes (PMax)

What are Search Themes?

Search Themes give you back a degree of control in Performance Max: you explicitly tell the AI which search topics are relevant instead of relying solely on automatic signal collection. This is especially valuable for new campaigns without conversion history or in niche industries whose technical terms Google doesn’t automatically recognize. Use Search Themes strategically to shorten your campaign’s learning phase and reduce wasted spend.

Search Themes are a control feature in Performance Max that let you tell Google which search queries your campaign is relevant for. Unlike keywords in search campaigns, Search Themes are not hard targeting criteria but hints that the algorithm uses as a starting point for its own optimization. You can store up to 25 Search Themes per Asset Group.

The feature was introduced to address PMax’s biggest weakness: the lack of control over search queries. Before Search Themes, Google relied entirely on inferring relevant search queries from your assets and landing pages. With Search Themes, you can actively steer the algorithm in the right direction, especially for new campaigns without historical data.

For practical use, it’s recommended to derive Search Themes from your successful search campaign keywords. Use top-performing search terms as themes and add broader topic areas that describe your offer. Avoid themes that are too generic, as they lead to wasted spend. Combine Search Themes with Asset Group Signals for more precise control. Regularly review PMax’s search terms report and exclude irrelevant terms via Brand Exclusions and negative keywords.