Website Speed Optimisation: Faster Pages and Better Core Web Vitals
A slow website loses people before they read a word. Pages that take too long to load, buttons that lag when tapped and layouts that jump while loading all make visitors less likely to stay, enquire or buy. Net Branding Limited provides website speed optimisation for New Zealand and international organisations, using Google’s Core Web Vitals as the measure of success rather than a single test score.
Want to know how your website performs for real visitors? A free audit checks your Core Web Vitals and page speed and explains what is slowing your site down.
Signs your website is too slow
Speed problems are easy to miss when you always visit your own site on a fast office connection. Your customers often see something different, on older phones, patchy mobile data or busy networks.
These are the signs we look for:
- The main image or heading takes several seconds to appear on a phone.
- Buttons and menus feel sticky, or nothing happens for a moment after a tap.
- Text or buttons jump down the page as images, banners or adverts load.
- Google Search Console shows URLs marked “Poor” or “Needs improvement” in the Core Web Vitals report.
- PageSpeed Insights flags large images, render blocking resources or long tasks.
- Visitors leave forms or checkouts part way through.
Each of these points to a specific cause. Slow loading is often images, fonts or server response. Laggy taps usually come from heavy JavaScript. Jumping layouts come from content that loads without reserved space. Website speed optimisation identifies which problems your site actually has, so effort goes where it makes a difference.
Core Web Vitals explained
Core Web Vitals are a set of metrics from Google that measure real world user experience. According to Google’s own documentation on web.dev and Google Search Central, the current Core Web Vitals and their good thresholds are:
| Metric | What it measures | Good threshold |
|---|---|---|
| Largest Contentful Paint (LCP) | Loading: how quickly the main content appears | Within 2.5 seconds of the page starting to load |
| Interaction to Next Paint (INP) | Responsiveness: how quickly the page reacts to clicks, taps and key presses | 200 milliseconds or less |
| Cumulative Layout Shift (CLS) | Visual stability: how much the layout moves unexpectedly | 0.1 or less |
Interaction to Next Paint has replaced First Input Delay as the responsiveness metric. Some older guides still refer to First Input Delay, so check the date on any advice you read.
Google recommends measuring at the 75th percentile of page loads, segmented across mobile and desktop. A page passes when it meets all three targets at that level. In practice, this means most of your real visitors need a good experience, not just people on fast connections.
Google Search Central states that it highly recommends site owners achieve good Core Web Vitals for success with Search and for a good user experience generally. Speed is one part of page experience. It does not replace relevant, helpful content.
Lab scores and real user data
One of the most common sources of confusion is the difference between a PageSpeed Insights score and your Core Web Vitals.
PageSpeed Insights shows two kinds of data:
- Field data comes from the Chrome User Experience Report, which collects anonymised measurements from real Chrome users. This is what the Core Web Vitals assessment is based on.
- Lab data comes from Lighthouse, which tests the page once in a simulated environment and produces the familiar score out of 100.
Lab tests are useful for diagnosing problems and checking changes before they go live. They are not what real visitors experience. A page can score modestly in the lab and still pass Core Web Vitals in the field, or the other way round. Lighthouse also cannot measure Interaction to Next Paint directly, so it uses Total Blocking Time as a stand in.
Some agencies promise a particular lab score. We focus on field data, because that reflects your actual visitors and is what Google’s Core Web Vitals report uses. We use lab tools to find causes and confirm fixes, then watch the field data as it updates. Smaller sites sometimes do not have enough traffic for field data, in which case we rely on lab testing and careful monitoring.
Core Web Vitals fixes we make
Our Core Web Vitals fixes target the specific causes behind each metric. Not every site needs every fix, so we start with the issues that affect the most visitors.
Fixing slow loading (LCP)
Largest Contentful Paint usually depends on four things: how quickly the server responds, how soon the browser discovers the main image or text, how long that resource takes to download, and whether anything blocks it from appearing.
Typical fixes include:
- Compressing and resizing images, and serving modern formats such as WebP or AVIF.
- Making sure the main image is not lazy loaded and is discovered early.
- Reducing server response time through caching and better hosting.
- Removing or deferring render blocking CSS and JavaScript.
- Loading web fonts efficiently so text appears quickly.
Fixing laggy interactions (INP)
Interaction to Next Paint suffers when the browser is busy running JavaScript and cannot respond to a tap or click.
Typical fixes include:
- Removing unused scripts and plugins.
- Delaying third party code, such as chat widgets and tracking tags, until it is needed.
- Breaking up long tasks so the browser can respond between them.
- Simplifying heavy page builder layouts and sliders.
Fixing jumping layouts (CLS)
Cumulative Layout Shift happens when content moves after the page has started showing.
Typical fixes include:
- Setting width and height on images and video embeds.
- Reserving space for banners, adverts and embedded content.
- Loading fonts in a way that avoids text reflowing.
- Avoiding content inserted above what the visitor is already reading.
Not sure which of these your site needs? Talk to Cathy and we will explain what we found and what is worth fixing first.
Page speed NZ: hosting, distance and third party code
New Zealand websites face a few speed challenges of their own. Distance matters on the internet. If your website is hosted a long way from your visitors, every request travels further and takes longer. For a site serving mostly New Zealand customers, hosting in or near New Zealand, or using a content delivery network with nearby locations, can reduce that delay.
Other common causes of slow page speed in NZ include:
- Budget shared hosting that struggles when traffic rises.
- Tracking tags and marketing scripts added over the years and never removed.
- Booking, chat and review widgets that load heavy code on every page.
- Large hero videos and image sliders on the homepage.
- Older themes and page builders that load far more code than the page uses.
We review each of these with you. Some are quick wins, such as removing a script nobody uses. Others involve trade offs, such as keeping a booking widget but loading it only on the pages that need it. If hosting is the bottleneck, our managed website hosting can move your site to an environment set up for speed. If the site itself is built on outdated foundations, a website redesign may be the better long term fix.
How speed connects to technical SEO and AI search
Speed sits alongside crawling, indexing and structured data as part of the technical foundation of your website. A fast, stable page is easier for people to use, and it supports the page experience Google’s ranking systems seek to reward.
Speed work and technical SEO overlap in several places:
- Faster server responses help crawlers move through your website efficiently.
- Clean HTML and less reliance on heavy JavaScript make content easier for search engines and AI tools to read.
- Removing redirect chains improves both load time and crawl efficiency.
- Image optimisation improves loading and supports image search.
This page focuses on the development side: code, images, scripts, themes and hosting. Our technical SEO services cover the search side, including crawl and indexing fixes, canonical tags, sitemaps and structured data. Many clients need both, and we keep the priorities clear so neither undoes the other. A full SEO audit is the best starting point if you want speed reviewed alongside content and links. For how AI tools access and describe your organisation, see our AI search services.
Our website speed optimisation process
Net Branding Limited has worked in digital marketing since 2008, with online experience before that. Cathy Mellett, our director, oversees speed projects and makes sure you understand what is changing and why.
Our process:
- Measure. We record field data from Search Console and PageSpeed Insights, plus lab tests for key page templates, so there is a clear baseline.
- Diagnose. We identify the causes behind each poor metric and estimate the effort and impact of each fix.
- Prioritise. We agree with you which fixes to make first, starting with templates that affect the most pages and visitors.
- Fix and test. We make changes on a staging copy where possible, then check that layout, forms and tracking still work.
- Monitor. Field data updates over a rolling period, so we keep watching after launch to confirm real visitors see the improvement.
We work on WordPress websites, online stores and custom builds. For stores, speed work often focuses on product pages, category filters and checkout, and our ecommerce website service covers the wider build.
Costs depend on your platform, the number of templates and how much third party code is involved. Our website pricing page explains how we scope development work, and we provide a written quote before starting. We do not guarantee rankings, traffic or AI citations, and we do not promise a particular lab score. We focus on measurable improvements for real visitors. Read our Google reviews to see what clients say. See all our website services.
Frequently asked questions about website speed
What is website speed optimisation?
Website speed optimisation is the work of making pages load faster, respond quickly to taps and clicks, and stay visually stable. It covers images, code, scripts, fonts, caching and hosting, measured against Google’s Core Web Vitals.
What are good Core Web Vitals scores?
According to Google, a good Largest Contentful Paint is within 2.5 seconds, a good Interaction to Next Paint is 200 milliseconds or less, and a good Cumulative Layout Shift is 0.1 or less, measured at the 75th percentile of page loads.
Why does my PageSpeed Insights score change every time I test?
The score comes from a single lab test, which varies with network conditions and server load at that moment. Field data from real users is more stable and is what the Core Web Vitals assessment uses.
Will speed optimisation change how my website looks?
Usually not. Most fixes happen behind the scenes. Occasionally we recommend changes, such as replacing an autoplay video or a heavy slider, and we discuss these with you first.
How long before I see results?
Lab improvements show straight away. Field data in Search Console and PageSpeed Insights is based on a rolling window of recent real visits, so it takes several weeks to fully reflect the changes.
Does website speed affect Google rankings?
Google says good Core Web Vitals align with what its ranking systems seek to reward, as part of page experience. Speed alone will not make a page rank. Relevant, helpful content still matters most.
Can you speed up my site without changing hosts?
Often, yes. Many gains come from images, scripts and caching. If server response time is the main bottleneck, we will explain the hosting options and let you decide.
Ready for a faster website? Call 09 523 0478 or email cathy@seocompanynz.com to get a quote for speed optimisation scoped to your website and its real visitors.