Website Speed and SEO: How Page Speed Affects Google Rankings
Website speed has become an important part of SEO and the overall experience visitors have on your website. A slow website can make it harder for visitors to find what they need, increase the chance of them leaving and, in some circumstances, make it harder for your pages to compete in Google Search.
But website speed is only one part of SEO. A fast website with poor content won't suddenly outrank a slower website that provides a much better answer to a search query.
So, how important is website speed for SEO, what does Google actually measure, and what can you do if your website is slow?
Does Website Speed Affect SEO?
Yes, but not in the way you might think.
Google uses a range of signals to determine which pages should appear in its search results. These include the relevance and quality of the content, the authority of the website and various aspects of the page experience.
Core Web Vitals are included in Google's ranking systems and are designed to measure real-world aspects of a website's performance, including loading speed, responsiveness and visual stability. Google recommends that websites achieve good Core Web Vitals for both Search and the experience of their visitors.
However, there is no magic loading time that will make a page rank at the top of Google.
For example, if two websites provide similarly useful information, the website that provides a better overall experience may have an advantage. But improving your page speed won't compensate for poor content, weak relevance or a lack of authority.
Think of website speed as one part of a wider SEO strategy, rather than the entire strategy.
What are Core Web Vitals?
Core Web Vitals are three measurements that Google uses to assess important parts of the experience people have when visiting a web page.
Largest Contentful Paint (LCP)
LCP measures loading performance.
It looks at how quickly the largest main piece of content becomes visible to the visitor. This might be a large heading, image or other prominent element on the page.
Google recommends an LCP of 2.5 seconds or less for a good user experience.
A slow LCP can be caused by things such as large images, slow server response times, render-blocking resources or poorly optimised code.
Interaction to Next Paint (INP)
INP measures how quickly a website responds when someone interacts with it.
This is particularly important for websites with interactive elements such as navigation menus, product filters, forms, calculators or other tools.
Google recommends an INP of less than 200 milliseconds.
A page might appear to have loaded quickly but still feel slow if clicking a button or opening a menu results in a noticeable delay.
Cumulative Layout Shift (CLS)
CLS measures visual stability.
Have you ever tried to click a button on a website only for the page to move just as you click it? That's the sort of problem CLS is designed to identify.
Google recommends a CLS score of less than 0.1.
Layout shifts can be caused by images without defined dimensions, advertisements, dynamically loaded content, fonts or other elements being inserted into the page after it has started loading.
What makes a website slow?Poorly optimised code
Unnecessary code, inefficient database queries, excessive plugins and other technical issues can all contribute to slower websites.
This is where simply installing another optimisation plugin isn't always the answer.
Sometimes the underlying cause needs to be identified and fixed.
What makes a website slow?Large images
High-resolution images or files can contain far more data than a website actually needs.
A photograph uploaded directly from a modern camera or phone could be several megabytes in size. Displaying that image at a much smaller size on a website wastes bandwidth and can significantly increase loading times.
Images should be appropriately sized, compressed and served in suitable formats.
What makes a website slow?Slow hosting
The server has to respond to a visitor before the browser can start receiving and processing the page.
If the underlying hosting environment is slow or overloaded, it can affect the performance of the entire website.
This is one reason we don't treat hosting as an afterthought at Spiderscope. The hosting environment is part of the website's infrastructure, so it needs to be considered when diagnosing performance problems.
What makes a website slow?Too much JavaScript
JavaScript allows websites to provide interactive features, but excessive or poorly optimised JavaScript can delay how quickly a page becomes usable.
This can be particularly noticeable on mobile devices.
Analytics, live chat, advertising, social media feeds, tracking tools and other third-party services can also add additional requests and processing to a page.
Individually these may seem insignificant, but several third-party services can add up.
What makes a website slow?Too many redirects
Sometimes redirects are unavoidable, but you need to bear in mind that every redirect you set up is adding an additional HTTP request, which will slow your website down.
We suggest running a check of all existing redirects every few months to check for any unnecessary chains or loops. Removing or consolidating these into a direct path reduces the number of server requests.
Where redirects are necessary, ensure they’re implemented as 301 redirects to maintain search engine ranking signals.
How do you check your website speed?
There are several useful tools for checking website performance.
Google PageSpeed Insights
PageSpeed Insights is useful for testing individual pages and identifying potential performance improvements.
It provides both performance measurements and recommendations for things that could be improved.
However, it's important not to treat the score itself as the goal.
A website doesn't need a perfect 100 score to perform well in Google. Google itself warns that trying to achieve a perfect score purely for SEO purposes may not be the best use of your time.
Instead, look at why the page is slow and whether the recommended improvements are likely to make a meaningful difference to visitors.
Google Search Console
Search Console provides a Core Web Vitals report showing how groups of pages perform based on real-world data.
This can be particularly useful because it helps identify performance problems affecting multiple pages rather than simply showing what happens during one individual test.
Lighthouse Audit Tool
Lighthouse is built into Chrome's developer tools and can be useful when investigating specific performance problems.
It provides additional information that can help developers understand what is happening behind the scenes.
How can you improve website speed?
The right solution depends on what's actually making the website slow.
Some improvements are relatively straightforward. Others require development work.
For example, replacing a large image may be a simple content change, whereas reducing the amount of JavaScript executed on a page may require changes to the website itself.
That's why we recommend diagnosing the problem before deciding on the solution.
A list of recommendations from PageSpeed Insights doesn't necessarily tell you which changes will have the greatest real-world benefit.
Website speed is only one part of SEO
It's important not to lose sight of the bigger picture.
A successful SEO strategy normally involves several areas working together.
Technical SEO
Search engines need to be able to crawl, understand and access your website properly.
This includes things such as site structure, indexing, canonical URLs, structured data, redirects, performance and many other technical elements.
Page Content
Your pages need to provide useful information that matches what people are searching for.
Google's guidance places strong emphasis on helpful, reliable, people-first content rather than content created simply to attract search traffic.
Website experience
Visitors should be able to use your website easily, whether they're browsing on a desktop, tablet or mobile phone.
Speed is an important part of this, but so are navigation, readability, accessibility and the overall design of the site.
Authority
Links and other signals can help Google understand the reputation and authority of a website.
A technically perfect website still needs to establish why it deserves to appear prominently for competitive searches.
Is your website running slow?
If your website is slow, we can investigate what's causing the problem and recommend the changes that are most likely to make a real difference.
