What Is a Responsive Search Ad (RSA)?
A Responsive Search Ad is the standard text ad format in Google Ads.
Rather than writing a single fixed ad as advertisers once did with Expanded Text Ads, an RSA lets you supply up to 15 different headlines (each up to 30 characters) and up to 4 descriptions (each up to 90 characters).
Google's machine learning engine then assembles these assets into combinations and tests them across real auctions, learning over time which groupings generate the best click-through and conversion rates for different queries and users.
At any given moment, Google will display up to 3 headlines and 2 descriptions from your pool of assets.
Because the combinations are tested dynamically, a well-built RSA can effectively function as dozens of different ads running simultaneously, each tailored to the context of the search.
This is a significant advantage over manually split-testing individual ads, which takes weeks of data collection before you can draw meaningful conclusions.
The ad strength indicator in Google Ads gives you a signal of how well your RSA is set up. Ratings range from "Poor" to "Excellent" and are based on the quantity and variety of your assets.
Reaching "Good" or "Excellent" generally correlates with better performance, though it is worth noting that ad strength measures asset diversity rather than business results.
A campaign managed by an experienced Google Ads specialist will balance asset variety with precise messaging that reflects the brand and the intent behind each keyword group.
Google retired Expanded Text Ads in June 2022, making RSAs the only editable search ad format available for new campaigns. Understanding how to write and structure RSA assets is now a foundational skill for any South African business running paid search advertising.
Responsive Search Ad In Practice
Consider a Johannesburg-based home security company running a campaign targeting queries like "alarm installation Johannesburg" and "home security systems Sandton".
A well-structured RSA would include headlines covering the service type ("Professional Alarm Installation"), a local signal ("Serving Johannesburg and Sandton"), a credibility marker ("PSIRA Accredited Installers"), a benefit ("24/7 Armed Response"), and a call to action ("Get a Free Quote Today").
The description assets might cover pricing anchors in rand, response time guarantees, and installation timelines.
By pinning a headline like the company name to position 1 while leaving the remaining slots flexible, the advertiser ensures brand consistency without sacrificing the system's ability to optimise.
Over a few weeks, Google identifies that "24/7 Armed Response" paired with "Serving Johannesburg and Sandton" drives the most conversions, and serves that combination more frequently.
This kind of iterative, data-driven refinement is what makes RSAs significantly more efficient than static ad copy for competitive South African markets.
How Responsive Search Ads work
A Responsive Search Ad (RSA) is the standard Google search ad format in which you provide multiple headlines and descriptions, and Google's system automatically tests different combinations and serves the ones it predicts will perform best for each search. Rather than writing one fixed ad, you supply a set of assets, up to a defined number of headlines and descriptions, and the system mixes and matches them, adapting the ad to the query, device and context. This lets a single ad flex to different searches and continually optimise towards the best-performing combinations, using machine learning to do what manually testing every permutation could not. The trade-off is less control over exactly which combination shows, in exchange for automated optimisation across many variations, which is why providing varied, strong assets matters more than crafting one perfect ad.
Writing effective Responsive Search Ads
Because RSAs assemble ads from the assets you provide, performance depends on giving the system strong, varied material to work with. Provide as many distinct headlines as the format allows, covering different angles, benefits, features, calls to action, offers, and including the main keywords in some, so the system has range to match different searches. Ensure headlines make sense in various combinations, since they can appear in different orders, and avoid repetition across assets, which wastes the variety the format thrives on. Descriptions should expand on the value and reinforce the message. Pinning assets to fixed positions is possible but limits the system's optimisation, so use it sparingly. Reviewing which combinations and assets perform, and refreshing weak ones, keeps the ad improving. The shift from crafting one ad to supplying a strong, varied asset set is the key to effective RSAs.
FAQ
How many headlines should I use in a Responsive Search Ad?
Google recommends supplying all 15 headlines to give the algorithm maximum flexibility. More headline variety means more tested combinations, which helps the system identify top performers faster. Aim for headlines that cover different angles: features, benefits, location signals, and calls to action.
Are Responsive Search Ads better than Expanded Text Ads?
Yes. Google retired Expanded Text Ads in June 2022, making RSAs the only editable search ad format. RSAs typically achieve higher click-through rates because the system selects the combination most relevant to each query, rather than showing a single fixed message to every searcher.
How many headlines should you use in a Responsive Search Ad?
Provide as many distinct, strong headlines as the format allows, covering varied angles, benefits, features, offers and calls to action, and including keywords in some. More varied assets give the system greater range to match searches and optimise, so filling the available headline slots with genuinely different options generally improves performance.