Most people think about landing pages in terms of conversions. The page either works or it doesn't. Someone clicks your ad, they land on the page, and they either call, fill out the form, or leave. If the page converts well, great. If it doesn't, you need a better page. That's the obvious cost of a bad landing page, and most business owners understand it intuitively even if they haven't quantified it.
What most people don’t realize is that the same landing page is also affecting what you pay per click on every single ad in that campaign. Google evaluates your landing page as one of the three components of Quality Score, and Quality Score directly controls your cost per click. A page that loads slowly, doesn’t match the ad’s intent, or provides a poor mobile experience will drag your Landing Page Experience rating to "Below Average," which drops your Quality Score, which raises your CPC. You’re paying more per click and converting fewer of those clicks. Two penalties from the same page, compounding against each other.
This post is part of our 12-point Google Ads audit. We check landing pages as step 6 because by this point we’ve already identified what the ads are doing (conversion tracking, campaign performance, search terms, Quality Score, account settings). Now we’re looking at where the clicks actually go, and whether those destinations are helping or hurting.
How the Double Penalty Works
Landing Page Experience is one of three components Google uses to calculate Quality Score, along with Expected CTR and Ad Relevance. Based on Search Engine Land’s analysis of 15,000+ accounts, Landing Page Experience carries up to 3.5 of the possible 10 Quality Score points. That’s the same weight as Expected CTR and more than Ad Relevance. So a landing page problem can tank your Quality Score just as badly as terrible ad copy, and the CPC penalty is identical.
To put numbers on it: if your Landing Page Experience is "Below Average" and that drops your overall QS from 7 to 4, you’re paying roughly 75% more per click than you were before, based on the QS multiplier table. On a campaign spending $5,000 a month, that’s an extra $3,750 in CPC overpay per month. Not because your keywords are wrong or your bids are too high, but because your page loads too slowly or doesn’t match what the ad promised.
Meanwhile, that same slow page is also losing you conversions independently of the CPC penalty. Research consistently shows about 7% conversion loss for every additional second of load time. A page that loads in 5 seconds instead of 2 loses roughly 21% of potential conversions before anyone even reads the content. So you’re paying more per click to send people to a page that loses a fifth of them before it finishes loading.
The math gets ugly fast.
What Google Actually Evaluates
Google has a separate crawler called AdsBot-Google that visits your landing pages approximately every two weeks when you have active campaigns running. It’s different from the regular Googlebot that indexes pages for organic search. AdsBot specifically evaluates landing page quality for paid ads, and what it finds directly affects your Quality Score.
AdsBot looks at four things. Page speed is the most measurable: your Core Web Vitals scores, specifically Largest Contentful Paint (LCP should be under 2.5 seconds), Interaction to Next Paint (INP should be under 200 milliseconds), and Cumulative Layout Shift (CLS should be under 0.1). These are evaluated at the 75th percentile, meaning 75% of your page views need to meet the threshold for the page to pass. Mobile and desktop are evaluated separately, and since over 80% of paid search traffic comes from mobile devices, the mobile score is what matters most.
Content relevance is the second factor. AdsBot compares your landing page content against the search terms that triggered the ads pointing to that page, over a rolling 90-day window. It also compares your page against competitors’ pages showing for the same searches. If someone searches "commercial HVAC repair" and your ad talks about HVAC repair, but the landing page is your homepage listing twelve different services with HVAC buried in the fourth paragraph, AdsBot picks up that disconnect. A dedicated page about commercial HVAC repair with the headline matching the search intent will score dramatically better.
Google also introduced a navigation experience model in 2025 that evaluates whether your landing page confuses visitors or leads them somewhere unexpected. Pages with deceptive redirects, confusing navigation, or unexpected destinations get flagged before the ad is even shown. They’re applying the same E-E-A-T quality standards from organic search to paid landing pages now, which actually benefits legitimate businesses with well-built pages.
The fourth factor is mobile-friendliness and trust signals. Responsive design, readable font sizes, touch-friendly buttons, HTTPS, visible contact information, and clear business identity. These are table stakes in 2026, but we still find accounts sending paid traffic to pages that aren’t properly responsive or have SSL certificate issues.
What Slow Actually Looks Like
We run PageSpeed Insights on every unique landing page during an audit. The results are rarely good on accounts that haven’t had a speed audit before, and sometimes they’re genuinely shocking.
On a multi-location dental account we audited recently, the landing pages were loading with LCP scores between 4.5 and 6.9 seconds on mobile. Every single location page was in the "Poor" range. The pages weren’t doing anything unusual. They had a hero image, some text, a form, and a map widget. But the theme was loading over 400KB of JavaScript that wasn’t being used on those pages, the images weren’t optimized, and a third-party chat widget was adding 2 seconds to every page load by itself. None of this was visible to someone just looking at the page on their laptop. On desktop it loaded in under 3 seconds. On mobile over a cellular connection, it was a disaster.
On an ecommerce account, the product pages that were receiving paid traffic were loading in 15 to 20 seconds on mobile. Close to 900KB of unused JavaScript from the site’s Shopify theme, uncompressed product images, and a review widget that loaded synchronously instead of lazy-loading after the main content. Desktop looked fine because it had enough bandwidth and processing power to brute-force through all that bloat. Mobile couldn’t. Since most of their paid search clicks came from mobile, most of their traffic was hitting a page that barely functioned on the device they were using.
In both cases, the businesses had no idea their pages were slow on mobile. They checked their own sites on their office computers and everything seemed fine. Nobody had run a mobile speed test or looked at Core Web Vitals data. The Quality Score penalty had been quietly inflating their CPCs for months, and the conversion loss was being attributed to "the market being competitive" or "people just browsing." The actual problem was the page itself.
Why Your Homepage Is the Wrong Destination
One of the most common landing page mistakes in Google Ads is sending all paid traffic to the homepage. It seems logical. The homepage is the "front door" of the business. It has everything on it. But that’s exactly why it performs poorly for paid search traffic. Someone who searched for a specific service and clicked an ad about that specific service lands on a page that talks about fifteen things, and the service they searched for might be three scrolls down or behind a navigation click. The intent match is gone.
The data on this is consistent across industries: dedicated landing pages that match the ad’s promise convert 2-3x higher than homepages for paid traffic. One case study showed a jump from 3.1% to 8.4% conversion rate in six weeks just by building a dedicated page that matched the ad copy and removing the site navigation. That’s not a redesign. That’s one page with one message and one action.
The Quality Score impact is just as significant. A homepage targeting "everything" can’t score well on relevance for any specific search term because the content is too broad. A dedicated page about the exact service the person searched for, with a headline that matches their query, with content that goes deep on that one topic, will always score better on Landing Page Experience than a generic homepage. Better QS means lower CPCs on every click that campaign generates.
This doesn’t mean you need custom landing pages for every keyword. But your highest-spend campaigns should be sending traffic to pages built specifically for those campaigns, not to a homepage that tries to be everything to everyone. If you’re spending $3,000 a month on a campaign and sending it to your homepage, building a dedicated page for that campaign will almost certainly pay for itself within the first month through higher conversions and lower CPCs combined.
The Stuff That’s Broken and Nobody Checks
Beyond speed and relevance, there’s a category of landing page problems that only surface when you actually visit the page on a phone and try to do what a customer would do. We use browser automation on every audit to load each landing page on a simulated mobile device and check whether the conversion actions actually work.
On one service business we audited, three out of five location pages had a scheduling widget that didn’t render on mobile. The widget worked perfectly on desktop, and the development team had tested it on desktop. But on mobile Safari and Chrome, the iframe that contained the scheduler loaded to a height of zero pixels. The "Book Now" button was there, the page looked normal, but clicking it did nothing visible on a phone screen. Three locations had been running ads to a page where the primary conversion action was invisible on the device most people were using to find them.
We’ve also seen forms that cut off below the fold on smaller screens so the submit button is invisible, phone numbers displayed as plain text instead of clickable tel: links (so mobile users have to memorize the number and switch to their dialer), and chat widgets that cover the call-to-action button on mobile so the thing the visitor came to do is physically blocked by a "Can I help you?" popup.
None of these issues show up in a speed test. PageSpeed Insights will tell you the page loads in 2.1 seconds and passes all Core Web Vitals, and the page will still convert at zero percent because the form doesn’t work on a phone. You have to actually visit the page on a mobile device and try to convert. Most agencies never do this. Most businesses check their own site on a desktop computer once and assume everything is fine.
How to Check Yours
Two checks, five minutes each.
Check 1: Page speed. Go to pagespeed.web.dev and enter the URL your ads are pointing to. Make sure you’re looking at the Mobile tab, not Desktop. Look at the LCP number first. If it’s under 2.5 seconds, you’re in the green zone. Between 2.5 and 4 seconds, it’s dragging your Quality Score down and you’re leaving money on the table. Over 4 seconds, you have an active problem that’s inflating your CPCs and losing conversions every day the page stays live. Run this test on every unique URL in your Google Ads account, not just your homepage.
Check 2: Mobile functionality. Open your phone, go to the landing page your ads point to, and try to do what a customer would do. Try to fill out the form. Try to call the number. Try to book an appointment. Try to add something to the cart. Do this on the actual page the ad links to, not your homepage. If anything doesn’t work, doesn’t display correctly, or requires you to pinch and zoom to interact with it, that’s what your paid traffic is experiencing every day.
For the Quality Score side, go to your Google Ads account, navigate to the keywords view, and add the "Landing page exp." column. Sort by cost descending so you’re looking at the keywords spending the most money. If most of your high-spend keywords show "Below Average" for landing page experience, your page is actively penalizing your CPCs and no amount of bid strategy changes or ad copy improvements will fix it.
How Long Fixes Take to Show Up
If you fix a landing page speed issue or improve content relevance, you won't see the Quality Score improvement immediately. AdsBot recrawls landing pages approximately every two weeks for active campaigns. After it recrawls and evaluates the updated page, QS changes typically appear within one to two weeks. Full stabilization takes four to six weeks because Google uses a 90-day rolling comparison window against your competitors' pages for the same search terms.
This means landing page improvements have a delayed return. You’ll see conversion rate improvements almost immediately because faster pages and working forms help visitors right away. But the CPC reduction from improved Quality Score takes a month or more to materialize. Both benefits are real, but if you fix your page speed and check your CPC two days later expecting a drop, you’ll be disappointed. Give it a full billing cycle before evaluating the CPC impact.
The flip side is that landing page damage also takes time to show up. If someone pushes a site update that breaks mobile speed or removes content that was matching search intent, you won’t see the QS penalty for two to four weeks. By the time you notice CPCs creeping up, the problem has been live for weeks. This is why we recommend running PageSpeed tests monthly on all active landing pages, not just when something seems wrong.
Why This Is Step 6
In our audit framework, landing pages come after Quality Score (step 4) because QS tells us whether there’s a landing page problem, and this step tells us what the problem actually is. If the Landing Page Experience component is showing "Below Average" on your high-spend keywords, we already know the page is an issue before we run a single speed test. The audit at this step is about diagnosing the specific cause so you know what to fix first.
This is one of the 12 steps in our full Google Ads audit process. If you want us to run PageSpeed and functionality tests on your landing pages and show you what it’s costing you, request a free audit and we’ll show you both sides of the penalty.
