How to Improve Your Google Ads Quality Score and Lower Your CPC

Quality Score is the metric in Google Ads that has the single most leveraged relationship to what you actually pay per click. A keyword at Quality Score 10 can unlock a CPC discount of up to 50% compared to the same keyword at Quality Score 5. In real terms, that is a £40 CPC dropping to £22 without changing your bid.

The reason most advertisers ignore Quality Score is that Google has progressively de-emphasised it in public communications, pushing attention toward automated bidding and broad match. But Quality Score, or more precisely the real-time ad quality signals that sit behind it, still directly feeds Ad Rank and therefore determines your actual cost per click. This guide explains exactly how each component works and gives specific, actionable fixes that move the number.

Quality Score is a 1 to 10 diagnostic score calculated at the keyword level. It appears in your Google Ads interface as a column you can add to the keywords tab. Google calculates it based on three components: Expected Click-Through Rate, Ad Relevance, and Landing Page Experience. Each component is rated Below Average, Average, or Above Average.

Quality Score is not the live signal Google uses in the actual auction. The real-time auction uses quality signals calculated at the moment of each search, which are more granular than the displayed score. The displayed score is a lagging indicator. But improving the three components that drive the displayed score does improve your real-time auction quality signals, which is what actually lowers your CPC.

Each component feeds Ad Rank differently. Use this as the map before you start changing copy or pages:

Component 1: Expected Click-Through Rate

Expected CTR measures how likely Google believes your ad is to receive a click when it is shown for a given keyword, based on historical CTR data adjusted for position. It is the most important of the three components because it is Google's assessment of whether your ad is actually relevant to what the user searched for.

An expected CTR rated Below Average means Google predicts your ad will earn fewer clicks than competing ads targeting the same keyword. This directly increases your CPC because, to win the same position as a higher-CTR competitor, you need to compensate with a higher bid. Two advertisers bidding identically, with one having expected CTR Above Average and the other Below Average, will pay materially different CPCs for the same position.

Improving expected CTR comes down to ad copy that more closely matches search intent than your competitors'. You need to test headlines that include the exact keyword phrase the user searched, numbers and specifics in headlines rather than vague claims, ad headlines that address the search intent directly (someone searching 'emergency plumber London' wants speed and availability, not price), and calls to action that match the stage of the buyer's journey for that keyword.

Component 2: Ad Relevance

Ad relevance measures how closely your ad copy aligns with the keyword. Below Average ad relevance typically means you have one ad set serving a wide range of keywords that span different intents, so no single ad is genuinely relevant to all of them.

The most common cause is oversized ad groups. When an ad group contains 30 or 40 keywords covering different topics or buyer intents, the same ad cannot be highly relevant to all of them. Google's guidance, supported by performance data, is that tighter ad groups with fewer, more closely related keywords consistently produce higher ad relevance scores.

The fix: audit your ad groups and identify where keyword themes are being mixed. Split ad groups so that each contains keywords with the same core intent and search behaviour. Rewrite the RSA headlines and descriptions to address that specific intent directly. Including the primary keyword naturally in at least one headline has been shown by multiple studies to improve CTR by 10 to 20%, which also feeds back into expected CTR scores.

This structural work is the same discipline that underpins good performance marketing campaign architecture. Tighter keyword grouping, more relevant ad copy, and cleaner campaign structure are not separate optimisation tasks, they are the same task done consistently.

Component 3: Landing Page Experience

Landing page experience is the component that most advertisers underinvest in because it sits outside the Google Ads interface.

Google evaluates landing page experience on several dimensions. Page load speed is measured with particular attention to the time from ad click to the page becoming usable on mobile. Pages loading above three seconds consistently score Below Average. Mobile-friendliness is assessed because over half of Google searches come from mobile devices. Content relevance is measured by whether the landing page content actually addresses what the user searched for. Transparency signals, including clear contact information, privacy policy, and absence of aggressive interstitial popups, all affect the score.

The relationship between landing page quality and CPL is direct and significant. A page converting at 4% generates twice the leads of one converting at 2% for identical ad spend. Improving landing page experience through Quality Score also reduces the CPC you pay to send traffic there, compounding the benefit.

Add the Quality Score column to your Keywords tab in Google Ads. Sort ascending to surface the lowest scores first. Then add the three component columns: Landing Page Experience, Ad Relevance, and Expected CTR. You are looking for keywords with Quality Score below 5 and at least one component rated Below Average.

Prioritise keywords by spend. A keyword with Quality Score 3 spending $500 per month is a much higher priority than a keyword with Quality Score 3 spending $5 per month. The CPC discount from improving the higher-spend keyword produces a larger absolute saving.

Do not try to fix every low-Quality Score keyword simultaneously. Pick the top three to five by spend, identify which component is Below Average for each, and make the specific structural or copy change that addresses that component. Check back in two to four weeks to see whether the score has moved. Quality Score updates as Google accumulates new click and impression data under the improved conditions.

These beliefs keep accounts overpaying even when the advertiser thinks they have already 'optimised':

Quality Score changes do not happen overnight. Google needs enough new impression and click data under the improved conditions before the displayed score updates. A keyword receiving 50 impressions per day will update its Quality Score faster than one receiving 5 impressions per day.

The most important operational principle: Quality Score improvement requires consistency, not one-off changes. Checking every few months, finding one or two ad groups with below-average components, and fixing the worst component first is how sustained improvement happens. Trying to fix everything simultaneously produces confusion about what changed and what actually moved the score.