SYS/DEF
Quality Score
Google Ads rating (1–10) mixing expected CTR, ad relevance and landing. A CPC lever, not SEO karma.
Definition
Quality Score is Google Ads’ estimate of the quality of the keyword / ad / landing set, from 1 to 10. It weights the actual bid: a low QS makes the same rank cost more. Its components (expected CTR, relevance, landing experience) are diagnostics, not scientific scores reproducible outside the platform.
It is not a Core Web Vital, nor an E-E-A-T score. A slow landing hurts QS and Vitals, for different reasons.
When it matters
When CPA spikes at stable conversion (often QS or the bid), when a new landing is wired onto an existing campaign, when the ad’s intent and the page’s intent diverge.
A CRO test on the landing can improve QS (better post-click CTR, bounce); the reverse is not automatic. Measure CPA/ROAS, not only the coloured pill.
Pitfalls
Optimising QS for QS: stuffing the keyword into the H1, ignoring intent. Comparing QS across networks (Search vs Display). Reading a 7/10 as a weekly truth when it is smoothed. Sacrificing business conversion for a misleading ad CTR — QS rises, ROAS falls.
Related terms
Related tool
QS influences the denominator (cost); the tool computes what the campaign actually cost and returned: Open CPA and ROAS.