Why your Google Ads cost per click suddenly went up, and how to check each cause

Your cost per click most likely went up for one of five reasons: Quality Score decay, new competition entering your auctions, broad match keywords drifting into worse queries, seasonality, or a landing page change that Google has downgraded. Each has a self-check you can run inside your own account in a few minutes, and the order below is the rough order of likelihood I see in takeover work.

Work through them in sequence. Most people jump straight to "a competitor is outbidding us" because it flatters the account, but the internal causes are more common and entirely within your control.

Has your Quality Score decayed?

Quality Score is Google's rating of each keyword built from three parts: expected clickthrough rate, ad relevance and landing page experience. Low scores raise your cost per click, because Google charges you more to show a less relevant ad. It decays quietly when ads go stale, when keywords and ad copy drift apart, or when the landing page changes.

The self-check: at keyword level, add the Quality Score columns, including the three component columns. If keywords carrying most of your spend show below-average expected clickthrough rate or landing page experience, you have found a cause that costs nothing but work to fix, through tighter ad groups, ads that mirror the query, and pages that deliver what the ad promised.

Did a new competitor enter your auctions?

When a new advertiser bids on your keywords, auction prices rise for everyone. The self-check has two parts. Inside your account, open the Auction Insights report and look for a domain that appeared or grew around the date your costs jumped. Outside your account, look the suspect up in Google's Ads Transparency Center at adstransparency.google.com, which shows every advertiser's ads, when they last ran and in which regions, with no login required. I walk through that tool properly in how to check if a company is running Google Ads.

If a genuine new entrant is bidding hard, you compete on relevance and landing pages rather than on bid alone, which brings you back to Quality Score.

Are broad match keywords expanding into worse queries?

Broad match keywords deliberately expand your reach beyond the literal keyword, which means they need negative keywords reviewed regularly to stay honest. Left alone, they drift into looser, more expensive, less relevant auctions.

The self-check: open the search terms report and read what people actually typed before clicking your ads. If the queries have wandered from your service, add negatives and consider tightening match types. While you are in the neighbourhood, confirm your Search campaigns have not also quietly opted into the Display Network, which distorts averages in its own way. I cover that leak in why your budget is going to random apps and websites.

Is it just the season?

Some markets get more expensive at predictable times because more advertisers pile in or demand shifts. The self-check is a comparison against your own history: put this period next to the same period last year rather than last month. If the pattern repeats annually, you are looking at your market's rhythm and the sensible response is planning around it rather than panicking within it.

Did your website change recently?

A site relaunch is a classic hidden cause. Relaunches commonly break conversion tags and redirects, and a new page that loads slower or matches the ad less well drags down landing page experience, which raises cost per click through Quality Score. Worse, broken tags starve smart bidding of the conversion data it optimises on, and it degrades without that data and re-learns slowly once it returns. If your costs jumped and your leads dropped around a relaunch, read our website relaunched and the leads disappeared.

What if none of these explains it?

Then stop trusting the numbers before you keep diagnosing. My standing rule is to fix measurement before judging campaigns, because a cost per click chart is only as honest as the tracking behind the account's decisions. The three receipts sets out the evidence a trustworthy setup produces. And if an agency runs the account and the increase came with vague explanations, put it through the checks in is my ads agency doing a good job. Every check on this page uses access you already have, so you can finish the diagnosis before deciding whether you need anyone's help at all.