Technical SEO
Core Web Vitals And Site Speed Diagnosis For Rankings
Find out whether page speed is genuinely holding back your rankings, and exactly what to fix if it is.
Most speed work optimises the wrong number. A perfect Lighthouse score is a lab result on a simulated device, while Google uses field data from real Chrome users, and the two routinely disagree. This service is the diagnosis: which templates fail Core Web Vitals on real traffic, what causes each failure, and whether fixing it is worth more than your next SEO priority.
Diagnosis here, fix work with dijitul support
We used to run separate site speed and Core Web Vitals pages. They were the same job seen from two angles, so they are now one service. What we deliver is the search diagnosis: field data by template, the specific element or script behind each failing metric, and a prioritised fix specification.
If you have a developer, they can work from that list. If you do not, the hands-on speed work (caching, image pipelines, theme and plugin clean-up, server tuning) is done by our sister company, dijitul support, and we re-check the field data once their changes have had time to show up.
You probably need this if
- Search Console reports poor or needs-improvement URLs under Core Web Vitals
- Lighthouse shows a high score but Search Console still reports failing URLs
- Interaction to Next Paint got worse after adding a tag manager, chat widget or consent banner
- Pages jump about as images, fonts and adverts load in
- You have been told speed is why you do not rank and want to know if that is true
What you get
- Field data analysis from the Chrome UX Report and Search Console, split by device and template
- The LCP element on each failing template and what delays it
- INP profiling down to the scripts and event handlers blocking the main thread
- CLS causes identified, with the exact elements responsible
- Server response time and third-party script review with a keep, defer or remove call on each
- A prioritised fix specification, weighed against your other SEO work
How we approach it
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Start with field data
Pull real user metrics from CrUX and Search Console and group by template, since one bad template can fail a whole group of URLs.
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Find the cause of each failure
Identify the actual LCP element, the long tasks behind poor INP and the elements that shift, testing on a throttled mobile connection rather than office broadband.
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Weigh it against everything else
Core Web Vitals is a real but modest ranking signal. We say plainly whether speed is your constraint or a distraction from a bigger problem.
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Hand over and re-measure
Your developer or dijitul support implements the fixes; we re-check field data over the following 28-day window, since that is the period CrUX reports on.
Core Web Vitals & Site Speed: common questions
Is Lighthouse score a ranking factor?
No. Lighthouse is a lab tool producing a diagnostic score on a simulated device. Google uses field data from real Chrome users, reported in Search Console and the Chrome UX Report. You can score 100 in Lighthouse and still fail Core Web Vitals.
How much do Core Web Vitals affect rankings?
They are a genuine but modest signal, mainly a tiebreaker between pages of similar relevance. The stronger commercial case is conversion, because faster pages lose fewer visitors before they act.
What replaced First Input Delay?
Interaction to Next Paint replaced FID as a Core Web Vital in March 2024. INP is harder to pass because it measures the latency of interactions throughout the visit, not only the delay before the first one.
What is a good page load time?
Google's thresholds for a good experience are Largest Contentful Paint within 2.5 seconds, INP within 200 milliseconds and CLS below 0.1, measured at the 75th percentile of real visits. Time to first byte is not a Core Web Vital but a slow server makes LCP very hard to pass.
Do you make the speed fixes yourselves?
We diagnose and specify. The fixes are made by your own developer or by dijitul support, our sister company, who handle hands-on speed work. We then confirm the improvement in the field data.
Find out what is actually holding you back
A short conversation and a look at your site is usually enough to tell you where the real problem is. No obligation, and no pressure to sign anything.