February 3, 2023

How to Audit Your Site Speed & Performance

Website speed and performance are massive parts of SEO and user experience. User experience is also incredibly important to Google because they can track how long a user stays on your website, whether they click through to any pages and, most importantly, whether they leave your site and click on someone else’s. In a Google Webmaster Video, it’s stated that “2 seconds is the threshold for eCommerce website acceptability”. If this doesn’t prove the importance of site speed then maybe this will: one study has shown that a site that loads in 1 second has a 3x increase in conversions as a site that loads in 5 seconds.

So, how do you audit site speed and performance? Website speed can be audited using various (free) tools available on different websites such as Google PageSpeed Insights, GTmetrix, ShortPixel, and DotCom-Tools. These tools give us more information about where speed and performance can be improved.

Read on for more information with a step-by-step explanation of how to audit site speed, along with information about why site speed should be considered for SEO and how we can improve any issues we find.

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How Do I Audit Website Speed?

To make improvements to a website’s speed we must first understand where the website is failing. Luckily, there are various tools we can use, free of charge, that give us a good idea of where improvements can be made. We’ll go through each tool, explain what the tools hope to achieve, and any potential opportunities they identify.

PageSpeed Insights by Google

PageSpeed Insights is a free tool from Google that gives us a look at how they rank your site speed and performance on both Mobile devices and Desktop.

Mobile Test:

Desktop Test:

The majority of websites have a worse mobile score than desktop score. It’s advised to have a score of at least 50 on mobile and at least 90 on desktop if possible. As we’re entering into a mobile-first world, mobile speed/performance will become more important, therefore prioritising mobile performance is a good idea moving forward.

Below are the data analyses of mobile and desktop. These focus on the metric times that do or do not need improvement. One of the main focuses we’re looking at is Largest Contentful Paint (LCP). This is how long the main content of a web page takes to load, which should not be any more than 2.5 seconds. Ideally, we’d like to make this less than 2 seconds. While Cumulative Layout Shift isn’t to do with site speed, this is another SEO factor within Core Web Vitals which needs to be 0.1 or less.



Google will then give advice regarding “Opportunities”. Shown within this area are the potential areas that can be fixed to improve the overall PageSpeed Insights score for desktop and/or mobile. It’s clear in this example that mobile has a few areas that need help, the main 3 include Reduce unused JavaScript, Reduce initial server response time, and Eliminate render-blocking resources.



DotCom-Tools Speed Test

DotCom Tools has a free speed test tool that’s used to test the page loading speed that users will see from different areas of the world. This tool tests the first and second visits because the second visit is usually faster due to a page or browser cache. We want around 2.0 seconds load time or less. Anything over 3.0 seconds needs to be fixed. If your website is for a business that only offers services located in a specific country or state, then the time to load the site within that area is the most significant.


GTmetrix is another free tool that helps analyse website speed performance.

GTmetrix offers similar advice to Google PageSpeed insights but also gives more information on other potential improvements such as using a Content Delivery Network (CDN) to serve pages in different geographic locations. CDNs cache pages on their servers in certain countries so that it loads faster the next time someone in that area or location goes on the website.


ShortPixel is a free tool used to see if you need to compress any images on your website. While it isn’t always fully accurate in terms of potential percentages of image compression, the website gives you a general idea of whether images could be compressed or served as new-gen files to improve overall loading times.

How Do You Improve Website Speed?

When attempting to improve website speed there are a few considerations. The first thing to consider is the Content Management System (CMS). If you’re on a CMS that limits access to certain areas of the administration area, such as the website code, it may be harder to improve website speed than if you had access.

Another thing to consider here is that, even if you do have access to these areas, you may have a hard time understanding or putting into practice the potential improvements. This is where you may need to hire a web developer, SEO expert, or site speed specialist.

Content Delivery Network

A Content Delivery Network (CDN) is a network of servers placed in many geographic locations throughout the world. This decreases the load times of the website within these locations by caching pages on the servers. If you’re looking for a reputable CDN, Cloudflare offers a free CDN service along with other security and performance services.

Reduce or Minify Code

Excess or unused code within websites is common. It’s therefore a good idea to reduce, remove, or minify code that would otherwise cause larger load times.

Compress Images

When an image is first saved it can usually be compressed to reduce irrelevant image data so it’s a significantly smaller size (in terms of load) but the image quality isn’t affected so much that it ruins user experience. With the creation of new-gen image files such as WebP, images can now be saved as this file type and served on websites to reduce loading times even more.


If your website is built on WordPress you have many options to improve website speed. Deactivating and deleting excess plugins has been shown to improve site speed and performance dramatically.

However, there are additional plugins that can help improve site speed. A backup from the host (not from a plugin) should always be downloaded before installing any plugin. These plugins include:

How Does Website Speed Affect SEO & Rankings?

Since 2010, Google has been using site speed as one of their ranking factors and has said on regular occasions that a faster site will help you rank better. However, rather than overall speed being a direct ranking factor, Google has included certain areas of site speed and other user experience metrics within their Core Web Vitals.

Website speed can affect user interactions on a website. While this is bad for conversions (i.e. sales or enquiries), this is worse for SEO. If a page is taking a large amount of time to load, a user will likely become frustrated, impatient, and/or bored, then click off the page back to Google to find a faster, more efficient website.

This shows Google that the slower website isn’t helpful to users, as the bounce rate from the website towards another website is high. This will then rank other, quicker websites higher as this shows Google those websites have helped users more effectively as there are more user interactions.

Technical SEO Services at Wildcat Digital

If site speed performance, tools and fixes are still leaving you a little confused or unsure of what you need to do, our expert SEO team at Wildcat Digital can help. Site speed is one of the first technical SEO tasks that we complete as part of your campaign to help get things moving in the right direction. Learn more about this in our recent blog post, What is a Technical SEO Audit & Why is it Important?.

 Get in touch with us today to learn more about our SEO services.

Post by

Paul Pennington

SEO Account Director

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