Google Ads search copy is written as a pool of assets, not a single ad. In a responsive search ad you supply headlines and descriptions, and Google assembles combinations to suit each search. Good copy therefore means many distinct, individually useful assets, and good testing means changing one idea at a time and judging by enquiries, not clicks alone.
How responsive search ads work
According to Google’s responsive search ad guidance, you can enter up to 15 headlines and 4 descriptions, and the minimum to create an ad is 3 headlines and 2 descriptions. Headlines are limited to 30 characters, descriptions to 90 and the two path fields to 15 each. In languages such as Chinese, Japanese and Korean each character counts as 2.
Because assets can appear in any order, Google advises that each one should make sense on its own and in combination with others. That rules out headlines that depend on the previous one, such as one that ends mid-thought.
Writing the asset pool
Think in categories rather than variations of one line. A balanced pool might include:
- What it is: the product or service in plain words, including the keyword people searched.
- Who it is for: a location, a customer type or a use case.
- Proof you can stand behind: only claims you can substantiate. Under Australian Consumer Law, claims must be accurate, so avoid superlatives you cannot back.
- Next step: a clear call to action such as “Request a quote”.
- Offer or difference: something real, such as a free consultation if you actually offer one.
Check that no two headlines say the same thing in different words. Near duplicates waste slots and teach you nothing. Keywords longer than 30 characters belong in a 90-character description rather than a headline, as Google notes.
Pinning: use it sparingly
Pinning fixes an asset to a position. Google explains that headline 1, headline 2 and description 1 always show when pinned, while headline 3 and description 2 are not guaranteed. Anything that must appear in every ad, such as a legal disclaimer, belongs in a guaranteed position. Pinning reduces the combinations available, and Google does not recommend it for most advertisers, so reserve it for genuine requirements.
What Ad Strength does and does not tell you
Ad Strength is a guide to how complete and varied your assets are. Google recommends at least 2 responsive search ads per ad group with a Good or Excellent rating. It is not a measure of business results. A high rating with weak messaging still produces weak enquiries, so judge ads by conversions and cost per enquiry from your own tracking.
Copy also interacts with the auction. Google’s Ad Rank page lists the bid, ad and landing page quality, minimum thresholds, competition, search context and the expected impact of assets and formats. Relevance between the ad and the page behind it matters, which is why message match is covered in landing pages that turn campaign traffic into enquiries.
A testing method that works
- Pick one question. For example: does a price-led message beat a service-led message?
- Change one theme. Replace a group of headlines about one idea with a group about another, and keep the rest.
- Use Google’s experiment tool for bigger tests. Its experiments guidance recommends running at least 4 to 6 weeks, or longer if conversions are slow, and notes the split cannot be changed after setup. That page is written mainly about Shopping and Performance Max experiments, so check the equivalent settings for search.
- Decide in advance what counts as a win. Choose the metric (qualified enquiries, not clicks) before looking at results.
- Record the result and what you will test next.
Small accounts may not see enough conversions to reach a firm conclusion. In that case, test bigger differences and accept directional answers rather than chasing tiny gains. The measurement thinking in how to measure creative campaign performance beyond views applies here, and the wider budget logic sits in building a digital marketing strategy.
Common mistakes
- Pinning every position, which stops other assets from showing.
- Testing three things at once and learning nothing.
- Ending a test after a few days.
- Writing copy that promises more than the landing page delivers.
Where Radiance Impact fits
Radiance Impact’s Growth division works on search visibility, campaigns and marketing strategy. If you want help structuring ad copy tests, see /growth or contact us.
Sources
- About responsive search ads, Google Ads Help
- About Ad Rank, Google Ads Help
- Experiments FAQs, Google Ads Help
