Pinning means fixing a headline or description to a particular position in a responsive search ad, so that it always appears in that slot whenever the ad shows. Everything you leave unpinned can still be shuffled by Google.
How pinning works
A responsive search ad holds up to 15 headlines and 4 descriptions. Google assembles them into different combinations for each search, choosing the mix it predicts will perform best. The finished ad has three headline positions and two description positions, though headline 3 and description 2 do not always appear, particularly on mobile.
When you pin a headline to position 1, only that headline can appear first. If you pin two or three headlines to the same position, Google rotates between them, so you keep some testing while still controlling what goes there. You can pin descriptions in the same way. Each pin reduces the number of combinations Google can try, and the Ad Strength rating usually drops as a result. Google describes Ad Strength as guidance on the ad’s variety rather than an input to the auction itself.
Why it matters
Unpinned ads can put headlines together in ways that read badly. “Book Online Today” followed by “Same-Day Appointments” makes sense; the reverse order may not. Some messages also need to sit together, such as an offer and its condition, or a price and what it covers.
For UK advertisers, pinning matters most when the wording has to meet rules. The CAP Code expects qualifications to sit close to the claims they qualify, and an ad that shows “50% Off All Courses” without the terms beside it can mislead. Financial firms, clinics and solicitors often have stricter requirements still. Pinning the qualifying line makes sure it is never dropped from the version people see.
The cost is reach and learning. A fully pinned ad behaves like an old expanded text ad: fewer combinations, less data about which messages work, and sometimes fewer impressions where Google judges a less relevant ad to be the best it can offer.
Common mistakes
- Pinning every headline to a position, which removes testing altogether.
- Pinning something essential to headline 3 or description 2, positions that are not guaranteed to show.
- Pinning a single headline when two or three similar options pinned to the same slot would keep control and still allow rotation.
- Writing unpinned headlines that only make sense next to one particular partner.
- Chasing an “Excellent” Ad Strength by removing pins that a regulator or the CAP Code effectively requires.
How to act on it
Start with as few pins as possible. Write headlines that each stand on their own, so any pair reads sensibly. Pin only where you have a reason you could explain to a colleague: the brand name in position 1 for a brand campaign, a required statement in description 1, or a headline that must lead because the next one depends on it.
When you pin, put two or three variants in the same position. A dental practice might pin “Private Dentist in Islington”, “Islington Dental Practice” and “Dentist Near Angel Station” to position 1, giving Google a choice while keeping the location first. Review the combinations report and the asset performance ratings after a few weeks, and replace the weakest unpinned headlines with new ideas.
Writing ads that work with or without pins is part of the setup and ongoing work in my Google search ads management.