What is Page Speed Optimisation?
Page Speed Optimisation refers to the techniques and strategies used to reduce the time it takes for a webpage to fully load and become interactive. It encompasses everything from compressing images and minifying code to leveraging browser caching and content delivery networks (CDNs). The goal is to deliver content to users as quickly as possible.
Why It Matters
Page speed directly impacts user experience and business outcomes. Research consistently shows that slower pages lead to higher bounce rates, lower conversion rates, and reduced engagement. Google has made page speed a confirmed ranking factor, meaning faster sites are more likely to rank higher in search results – a critical consideration for UK agencies managing organic visibility for clients.
For media buyers and marketers, page speed affects ad performance too. Slow-loading pages can increase ad latency, impact viewability rates, and frustrate users clicking through from paid campaigns. In competitive digital markets, every millisecond counts.
Key Metrics
Google's Core Web Vitals have become the industry standard for measuring page speed:
- Largest Contentful Paint (LCP): How quickly the main content loads (target: under 2.5 seconds)
- First Input Delay (FID): How responsive the page is to user interaction (target: under 100ms)
- Cumulative Layout Shift (CLS): Visual stability as elements load (target: under 0.1)
Optimisation Techniques
Common approaches include:
- Image optimisation: Compressing and serving appropriately-sized images
- Code minification: Removing unnecessary characters from CSS and JavaScript
- Browser caching: Storing static assets locally to reduce repeat load times
- CDN implementation: Distributing content across geographically-dispersed servers
- Server-side rendering: Pre-loading content to reduce processing time
- Lazy loading: Deferring the loading of off-screen content
When to Optimise
Page speed optimisation should be ongoing, but prioritise when:
- Launching new campaigns or landing pages
- Redesigning websites
- Noticing high bounce rates or low conversion rates
- Preparing for peak traffic periods (Black Friday, major promotional events)
- Competing in industries with speed-sensitive audiences (e-commerce, news, financial services)
Best Practice for Agencies
UK media agencies should make page speed audits routine, particularly when evaluating client websites for paid campaign landing pages. Tools like Google PageSpeed Insights, GTmetrix, and Lighthouse provide free diagnostics. Coordinate with development teams early to address bottlenecks before campaigns go live.