Fix Core Web Vitals — Without Re-launching Your Site
Measurable Lighthouse uplift, gated by CI so it sticks
Fix Core Web Vitals — done properly, by senior engineers
Core Web Vitals are the field metrics Google uses to judge real-world experience, and a "Poor" verdict on your highest-traffic templates is both a ranking risk and a conversion leak. The hard part is that the lab score in Lighthouse rarely matches what your actual users see — LCP can be dragged down by a single preloaded hero image or an RSC waterfall, INP by long tasks that only fire after hydration, and CLS by fonts, ads or late-injected banners. Our engineers work from your real Chrome User Experience and RUM data, not a one-off lab run, so we fix the issue your 75th-percentile visitor actually experiences. We trace each metric to its true root cause, ship the fix as a pull request you review, and then lock the gains in with synthetic and field monitoring so a future deploy cannot quietly undo the work.
What you're seeing
Search Console keeps flagging LCP, INP, and CLS as "Poor" on your highest-traffic URLs, and a CWV-driven ranking drop is around the corner.
Our approach
We diagnose each metric on production traffic, fix the root cause (not the symptom), and lock the gains in with synthetic + RUM monitoring. Pass-rate moves into "Good" within two sprints.
Symptoms teams come to us with
- Lighthouse and PageSpeed scores stuck in the red on mobile
- Visitors bounce before the hero or content paints
- Search Console flags Core Web Vitals as "Poor" on key URLs
- The site feels fast on your laptop but crawls on real phones
What we check first
- 01Oversized JavaScript bundles and unused third-party SDKs
- 02Render-blocking CSS, fonts and tag-manager scripts
- 03Unoptimised images and a missing modern image pipeline
- 04Slow TTFB from cold starts, slow queries or chatty APIs
What you get
Concrete deliverables, no fluff
Every engagement ends with measurable, documented outcomes — no black-box agency reports.
RUM-driven audit with line-level fix list
Implementation of every critical fix
Before/after metrics with screenshots
CI performance gate to prevent regression
What changes after we ship
LCP under 2.5s on field data
We trace the real LCP element — hero image, web font, or a blocking server component — and ship the fix that moves the 75th-percentile, not just the Lighthouse number.
INP into the "Good" band
We break up long tasks, defer non-critical scripts and schedule work properly so interactions feel instant after the first paint.
CLS below 0.1 and stable
We reserve space for every dynamic element, fix font-swap jank, and tame third-party tags so the layout stops jumping.
A CI gate so it never regresses
We wire a performance budget into CI and field monitoring so the next feature ship can't silently push you back into the red.
From brief to shipped fix
A transparent, low-risk process — a senior engineer reads your brief personally, and nothing starts until you approve a written plan and price.
Diagnose
A senior engineer reviews your brief, reproduces the issue, and pinpoints the real root cause — not the symptom — before any code is touched.
Scoped plan & quote
You get a written plan to fix Core Web Vitals, a firm timeline, and a fixed quote. Nothing starts until you approve it — no surprise invoices.
Ship the fix
We implement on a branch and open a pull request you review, working to your code-review standards on your repo — never a black box.
Verify & hand off
We verify on staging and production, share before/after evidence where it applies, and leave you a short hand-off note so the fix sticks.
Situations we handle
A CWV-driven ranking scare
Search Console flipped a template to "Poor" and organic traffic is wobbling. We stabilise the metrics before the drop compounds.
Lab passes, field fails
Lighthouse says 95 but CrUX says otherwise. We close the gap between the lab run and what real visitors on real phones experience.
A heavy marketing stack
Tag managers, chat widgets and A/B tools have quietly wrecked INP and CLS. We isolate the offenders and contain them without removing the tooling.
Why teams hand this task to Krapton
Senior engineers only
Your brief is read and handled by a senior engineer — no junior hand-off, no sales-rep filter in between.
Root cause, not a patch
We reproduce and fix the underlying cause, then add a guard so the same class of issue does not quietly return.
Your repo, your standards
Every change lands as a pull request you review, on your repository, following your existing review process.
NDA on day one
Confidentiality and IP are covered before we look at a single line of code. All work stays in your accounts.
Fixed quote up front
You approve a written plan and price before work starts. If scope changes, we re-quote in writing — no surprise invoices.
Proof, where it applies
Performance, SEO and reliability work ships with before/after evidence so the result is measurable, not anecdotal.
Three ways to engage
No retainer required. Pick the model that matches the work — pricing for this task starts from $1,500, with a fixed quote before anything starts.
Per task
Most popularOne clearly-scoped fix at a fixed price. Best when you know exactly what is broken and want it handled end to end.
- Fixed quote up front
- One PR, reviewed by you
- No retainer required
Hourly
Pay only for the hours worked. Best for diagnostics, audits, or exploratory work where the scope is still emerging.
- Weekly timesheets
- Pay for what you use
- No minimum commitment
Per sprint
A focused 1–2 week sprint when the work is bigger than one fix but smaller than a full project.
- 1–2 week blocks
- Clear sprint goal
- Scale up or stop anytime
Tooling we use
Industry-standard stack, no proprietary lock-in
Fix Core Web Vitals — your questions, answered
How much does it cost to fix Core Web Vitals?
Pricing starts from $1,500 and depends on the scope we find during the diagnostic. You get a fixed, written quote before any work begins — most engagements like this run 1–2 weeks.
How long does it take to fix Core Web Vitals?
Typically 1–2 weeks for a focused engagement. After a short diagnostic we commit to a firm timeline so you know exactly what to expect.
Will you work directly on our existing codebase?
Yes. We work on your GitHub, GitLab or Bitbucket, ship every change as a pull request you review, and follow your code-review standards — not ours.
What exactly will I have at the end?
Concrete, documented outcomes — RUM-driven audit with line-level fix list, Implementation of every critical fix, Before/after metrics with screenshots, and more. No black-box agency report.
How quickly can you start, and do you sign an NDA?
For a focused task like this we can usually start within 24–48 hours of the brief. We sign an NDA on day one, before we look at any code — yours or ours.
Will this improve my Core Web Vitals and Google rankings?
Directly. We fix the metrics Google actually ranks on — LCP, INP and CLS — on real-user data, then lock the gains in with monitoring so they don't regress. Better field metrics typically support better rankings on competitive queries.
Do you optimise for lab scores or real-user data?
Real-user (field) data first — that is what Google ranks on. We use your CrUX and RUM data to find what your 75th-percentile visitor actually experiences, fix that, and use Lighthouse only as a fast local signal, never as the goal.
How long before the improvement shows in Search Console?
Code changes are usually live within the engagement, but the Core Web Vitals report in Search Console is a 28-day rolling field average, so the official "Good" status typically updates over the following few weeks as new field data accumulates.
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Let's get this off your plate
Send a 60-second brief on Fix Core Web Vitals and a senior engineer replies within 24 hours with a plan and a fixed quote. NDA on day one, no retainer required.