What should I do about a campaign with stably low CVR but normal CTR and traffic volume?

The official diagnostic tool for this split is the same keyword-level Quality Score components used to diagnose ROAS. Ad Relevance covers traffic quality: how well the ad matches the intent behind the keyword. Landing Page Experience is a separate factor about what happens after the click.

The tag status: Active, Inactive, or Unverified, or Needs Attention, points directly to a tagging problem. Tag Diagnostics scans site tags with a quality report. The conversion tracking compatibility rate shows share of clicks trackable with a first-party cookie.

The Search Terms report shows which real queries triggered an ad. Ad Relevance measures whether the ad matches that query. Landing Page Experience measures whether the page matches the ad.

Under Target CPA or Target ROAS, device bid adjustments limited as "-100% only," since bids set automatically, already factoring in device.

The Landing pages page gives a breakdown by URL and lets you segment the table by device. Google states a one-second mobile delay in retail can affect conversion by up to 20 percent. The Mobile-friendly click rate column shows the share of clicks landing on a mobile-friendly page. Google provides PageSpeed Insights for raw speed measurement; comparable tools in the same category (GTmetrix, WebPageTest) work similarly.

The Ads Transparency Center lets you see whether competitors are showing on your own brand name. Brand exclusions settings let you manage brand traffic as its own segment.

Rule out measurement first: a tag showing Inactive or Unverified can look like a real CVR drop. If the tag is fine, break the path into steps to see exactly where the drop-off happens.