How Google Ads decides an ad's strength rating, and what it leaves out

Every responsive search ad in Google Ads carries a label: Incomplete, Poor, Average, Good or Excellent.

Google's documentation describes something narrower. Ad Strength is a feedback tool that grades the assets an advertiser supplies. It is not part of the auction, and it does not measure the landing page or the offer. Independent data on how it relates to results is mixed.

What a responsive search ad is built from

A responsive search ad is a pool of assets rather than a fixed ad. The advertiser supplies up to 15 headlines and up to 4 descriptions. Google Ads assembles them into combinations and learns which ones suit different queries.

Headlines are limited to 30 characters and descriptions to 90. Each ad shows at least one headline and one description, in varying orders. Headline 1 and Description 1 usually appear, while Headline 2, Headline 3 and Description 2 may appear but are not guaranteed.

Ad Strength grades that pool. The more distinct material the pool contains, the more combinations Google has to test, and the rating is designed to reflect that.

The four inputs behind the rating

Google lists four factors. The first is asset-keyword relevance: whether headlines and descriptions contain the advertiser's most relevant keywords. A keyword has to sit entirely inside one headline to improve Ad Strength, not be split across two. Keywords longer than the 30-character headline limit belong in descriptions.

The second is quantity. Google recommends using the full 15 headlines and 4 descriptions to maximise the combinations available.

The third is diversity. Headlines and descriptions should cover different selling points with minimal repeated words or ideas.

The fourth is sitelinks. Google counts both uploaded and dynamic sitelinks, and says at least six sitelinks, across the account, campaign and ad group levels, are needed for "Good+" Ad Strength. The rating recalculates when keywords, assets or account structure change, so an ad can move between labels without being edited.

What Ad Strength does not do

Google states that Ad Strength does not directly influence serving eligibility, and it is not used to calculate Ad Rank, Quality Score or auction wins.

The rating also does not measure landing page quality, the strength of the offer, or the benefit of adding new keywords. An ad can be Excellent while sending traffic to a weak page.

Common issues that produce an Incomplete label are no final URL, no ad group assigned, or no keywords in the ad group. In the last case the ad will not serve at all.

For a brand-new ad, only the assets the advertiser wrote are scored. Where text customization is switched on, Google-generated text counts equally with advertiser-written text, and the rating updates once those assets are added. Text customization is not available for Shopping ads.

Why pinning pulls the rating down

Pinning fixes an asset to a position. A pinned Headline 1, Headline 2 or Description 1 always shows. A pinned Headline 3 or Description 2 is not guaranteed to show.

Pinning reduces the number of assets that can be matched to a query, so Google's guidance is to avoid it for most advertisers. Where it is needed, for example for compliance, Google suggests pinning only one or two essential headlines and leaving the rest unpinned.

Pinning identical or near-identical text to the same position restricts the system and can lower Ad Strength. Google advises pinning two or three genuinely different assets to a position instead. If every position is pinned, unpinned assets do not show at all.

Optmyzr, a PPC software company, analysed more than 1 million ads from over 22,000 accounts in a study published on Sept. 9, 2024. Its accounts had run at least 90 days with monthly spend of at least $1,500. Ads with some pinning had the best cost per acquisition, with no pinning a close second. Conversion rates were lower when assets were pinned. The authors treat pinning as a brand or creative decision rather than a performance tactic.

Ad Strength is a feedback tool that grades the assets an advertiser supplies, not part of the auction.

What the performance data says

Google reports figures from its own internal data covering Aug. 15 to 20, 2025. Moving responsive search ads and sitelinks from Poor to Excellent was associated with about 15% more conversions on average. Going from one responsive search ad to two in an ad group was associated with 6.6% more conversions at a similar cost per conversion. Going from two to three added 3.7%.

The Optmyzr study found a different pattern for the rating itself. Ads rated Average had the best cost per acquisition, conversion rate and return on ad spend among responsive search ads. Return on ad spend dropped sharply from Average to Good and rose only slightly from Good to Excellent. Click-through rate showed no meaningful difference across labels.

Optmyzr's authors concluded there was no clear correlation between Ad Strength and performance and that it should not be a major optimisation focus. They also note possible selection bias, because Optmyzr customers are likely to be more advanced marketers.

The two sources measure different things. Google's figures describe changes that advertisers made, such as adding assets and sitelinks and running more ads. Optmyzr compared accounts grouped by the label they ended up with.

What to change first

Google's recommendations include these steps. The first is to run at least two responsive search ads per ad group rated Good or Excellent, each with its own final URL.

Next is to write assets that cover different selling points and avoid repeated words or ideas. Keywords belong inside single headlines, with long phrases moved to descriptions.

Then comes cleanup. Reduce pinning to one or two essential headlines, add at least six sitelinks, and consider adding four or more unique image assets and the business name and logo. Google also advises monitoring the rating over time, since keyword relevance can change.

The label identifies opportunities to improve an ad's construction. Ad Strength does not measure the landing page or the offerings.