Development
How to speed up your website: a practical guide
A step-by-step guide to making your website faster, from measuring Core Web Vitals to fixing images, scripts, fonts, caching and hosting.
Rapid Action Team · · 8 min read
Key takeaways
- Measure real-user performance first so you fix the problems visitors actually experience.
- Images and third-party scripts are the most common causes of slow pages on small business sites.
- Caching, compression and a CDN make every page faster with relatively little effort.
- Speed needs ongoing attention, because new plugins, tags and content slowly add weight.
A slow website frustrates visitors, wastes advertising spend and can hold back your search rankings. The good news is that most speed problems on small business sites come from a short list of causes, and many of them can be fixed without rebuilding anything.
This guide walks through how to measure your site's speed properly, then the practical fixes in roughly the order we would tackle them. Some you can do yourself in an afternoon; others are worth handing to a developer.
Why website speed matters
Speed affects almost everything a website is meant to do.
- Visitors: people are less patient on mobile, and a page that feels sluggish gives a poor first impression of your business.
- Conversions: every extra second between a click and a usable page is a chance for someone to give up.
- Search: Google uses page experience signals, including Core Web Vitals, as part of its ranking systems. Speed alone will not outrank better content, but it can make a difference between similar pages.
- Advertising: you pay for each click whether the page loads or not.
Measure before you change anything
Guessing wastes time. Start by measuring, so you know which pages are slow and why.
Use the right tools
- PageSpeed Insights: shows real-user data (where available) and a lab test with specific recommendations.
- Google Search Console: the Core Web Vitals report groups your pages by status across the whole site.
- Browser developer tools: the Network and Performance panels show exactly what loads and in what order.
- WebPageTest: detailed tests from different locations and connection speeds.
Understand Core Web Vitals
Google's Core Web Vitals are three measures of real-world experience. According to web.dev, these are the thresholds for a "good" score, assessed at the 75th percentile of page visits:
| Metric | What it measures | Good score |
|---|---|---|
| Largest Contentful Paint (LCP) | How quickly the main content appears | 2.5 seconds or less |
| Interaction to Next Paint (INP) | How quickly the page responds to taps and clicks | 200 milliseconds or less |
| Cumulative Layout Shift (CLS) | How much the layout jumps around while loading | 0.1 or less |
Optimise your images
Images are usually the heaviest part of a page, so they are the best place to start.
Resize before uploading
A photo straight from a phone or camera can be several thousand pixels wide. If it displays at 1,200 pixels, resize it to roughly that size, or a little larger for high-resolution screens.
Use modern formats
WebP and AVIF typically produce noticeably smaller files than JPEG or PNG at similar visual quality. Most CMSs and image tools can convert automatically.
Serve the right size for each screen
Responsive images let the browser download a smaller file on a phone and a larger one on a desktop. Frameworks such as Next.js do this for you with their image component; on other platforms, check that your theme outputs srcset.
Lazy load below-the-fold images
Images further down the page do not need to load straight away. Native lazy loading is one attribute:
<img src="/team.webp" alt="Our team" width="800" height="533" loading="lazy" />
Do not lazy load the main hero image, though. That is often your LCP element, and delaying it makes the score worse.
Always set dimensions
Giving images a width and height (or an aspect ratio in CSS) lets the browser reserve space, which prevents layout shift.
Cut back on JavaScript and third-party scripts
JavaScript is expensive: it has to be downloaded, parsed and run, which ties up the browser and slows interactions. Third-party scripts are a frequent culprit because they are easy to add and easy to forget.
Make a list of everything that loads on your pages, then ask whether each item is still needed:
- Chat widgets, pop-ups and survey tools
- Multiple analytics and tracking tags
- Social media feeds and share buttons
- Embedded videos and maps
- Sliders and animation libraries
- Old A/B testing snippets
Remove what you no longer use. For what remains, load it later where you can, for example after the page becomes interactive or only when a visitor clicks to open the chat. Embedded videos can show a lightweight preview image that loads the full player only on click.
Optimise CSS and fonts
Minify and remove unused CSS
Minification strips whitespace and comments from CSS and JavaScript. Most build tools and performance plugins do this automatically. Large themes often ship styles for features you never use, so removing unused CSS can help further.
Handle web fonts carefully
Fonts can delay text from appearing or cause it to jump when they load. A few habits help:
- Use fewer font families and weights.
- Self-host fonts rather than loading them from a third party where practical.
- Use
font-display: swapso text is visible while the font loads. - Preload the one or two font files used above the fold.
Use caching, compression and a CDN
Browser caching
Caching tells returning visitors' browsers to keep files such as images, CSS and JavaScript rather than downloading them again. Static files with versioned filenames can safely be cached for a long time.
Page caching
On database-driven platforms like WordPress, building each page from scratch for every visitor is slow. Page caching stores a ready-made version and serves that instead. Many hosts include it, or a reputable caching plugin can provide it.
Compression
Text files such as HTML, CSS and JavaScript compress very well. Check that your server uses Brotli or Gzip compression; most modern hosts enable it by default.
Content delivery network (CDN)
A CDN stores copies of your files on servers in many locations, so visitors download them from somewhere nearby. Even for a UK-focused business, a CDN can reduce load on your server and improve reliability.
Review your hosting and server response time
If your server takes a long time to respond, every other optimisation starts from behind. Time to First Byte (TTFB) is the measure to watch in your testing tools.
Signs your hosting may be the bottleneck:
- Slow TTFB even on simple pages
- Speed varies a lot at different times of day
- The site slows down sharply when traffic increases
- You are on a very cheap shared plan with many other sites
Moving to better managed hosting, a modern platform that serves pre-built pages from the edge, or a plan with more resources can make a large difference. Choose hosting with data centres or CDN coverage close to your customers.
Keep the platform lean
Audit plugins and apps
Each plugin can add scripts, styles and database queries. Deactivate and delete any you do not need, and replace several single-purpose plugins with one well-built option where possible.
Choose a lightweight theme or framework
Multipurpose themes with page builders tend to load a lot of code on every page. A lean theme, or a custom front end built in a modern framework, gives you far more control over what loads.
Tidy the database
Old post revisions, spam comments and leftover data from removed plugins can slow database-driven sites. Regular clean-ups, with a backup first, keep things efficient.
Keep everything updated
Updates to your CMS, plugins and server software often include performance improvements as well as security fixes.
A practical order of work
If you are not sure where to start, this order tends to give the biggest gains for the least effort:
- Measure your key pages and note the worst Core Web Vitals.
- Compress, resize and convert images; set dimensions; lazy load below-the-fold images.
- Remove unused plugins, apps and third-party scripts.
- Turn on page caching, compression and a CDN.
- Optimise fonts and defer non-essential JavaScript.
- Check TTFB and upgrade hosting if needed.
- Re-measure, then set a reminder to review speed every quarter.
Some fixes, such as reworking how scripts load or rebuilding a heavy theme, need developer time. Our frontend development team builds fast sites in Next.js and can also improve performance on existing platforms.
FAQs
What is a good page load time?
Rather than a single load time, aim for good Core Web Vitals: main content visible within 2.5 seconds, responses to interactions within 200 milliseconds and minimal layout shift, as defined by Google's web.dev guidance.
Why is my website slow on mobile but fine on desktop?
Phones usually have slower processors and less reliable connections, so heavy images and JavaScript hurt much more. Always test on mobile settings, as that is often where most of your visitors are.
Does website speed affect SEO?
Yes, to a degree. Core Web Vitals form part of Google's page experience signals. Relevant, helpful content matters more, but a faster site supports rankings and makes visitors more likely to stay.
Can I speed up my website without a developer?
Often, yes. Compressing images, removing unused plugins and enabling caching through your host can all be done without coding. Deeper issues with themes, scripts or hosting setup are usually best handled by a developer.
How often should I check my website speed?
Check after any significant change, such as a new plugin, tracking tag or redesign, and review your key pages at least every few months.
Want to know exactly what is slowing your site down? Request a free audit and we will send you a prioritised list of fixes, or book a call to talk it through with our team.
