Tips on Measuring and Improving Page Load Speed

What is Page Load Speed

“Page speed is a measurement of how fast the content loads on your page” (Moz, 2018).

Why is Page Load Speed Important?

Page load speed is important for SEO as it effects your google page rank and it also means that search engine crawlers can crawl fewer pages within their allocated budget which can negatively affect your indexisation.

It is also important for user experience because users expect pages to load quickly and they will not wait around with so many other options available to them elsewhere. According to Site Up Time, users wait no longer than 3 seconds for a page to load and half a second difference in load time can make a 10% difference in sales for online retailers.

47% of consumers expect websites to load in two seconds or less — and 40% will abandon a page that takes three or more seconds. A one-second delay in page load time yields:

– 11% fewer page views

– 16% decrease in customer satisfaction

– 7% loss in conversions

(The Daily Egg, 2018)

According to Shout Me Loud if an ecommerce site is making $100,000 per day, a 1 second page delay could potentially cost you $2.5m in lost sales every year.

Mobile vs Desktop

Overall people expect a similar performance from their mobile device as their desktop. Although they do generally have a lot more patience with their mobile device. According to a Shout Me Loud survey 31% of people said that they expect load times on their phone to be a bit slower but 25% they expect load times on their phone to be almost as fast and 21% said they expect them to be about equal.

However, in response to how long they would wait, 30% of people said they would wait 6-10 seconds, 30% said they would wait between 11-20 seconds, and 20% even said they would wait 20+ seconds.

How do we optimise page load speed?

Enable Compression

You can use software applications such a Gzip to reduce the size of your HTML, CSS and Javascript files.

Enabling gzip compression can reduce the size of the transferred response by up to 90%, which can significantly reduce the amount of time to download the resources. (PageSpeed Insights)

You can run a compression audit on your site using resources such as GIDNetwork to check compression on your site

Optimise Image Sizes

Ensure images are no larger than they need to be by optimising and compressing them using software such as Photoshop.

Also using CSS Sprites for icons combines multiple images into one, reducing http requests and meaning users don’t have to wait for multiple images to load 

Minifying Code

Minifying your code can dramatically improve your page speed. You can do this by removing unnecessary spaces, line breaks, comments.

Also ensuring you have removed any redundant code and using shorter variable or function names.

There are various plugins and other resources you can use such as HTMLMinifyer, CSSNano  and UglifyJS.

Browser Caching

Browsers cache a lot of information (stylesheets, images, JavaScript files, and more). This way the browser doesn’t have to reload the entire page each time a visitor comes back to your site.

Fetching resources over the network is both slow and expensive: the download may require multiple roundtrips between the client and server, which delays processing and may block rendering of page content

Be aware:

Make sure you set an expiry on your cache. Depending on how static your content is, some files could be anything between a week or a year.

How can we cache?

For WP sites you can use a plug in like W3 Total Cache to easily enable caching.

For static HTML you can enable caching in your .htaccess file


When you use Javascript in your webpage either put it in a separate file to your HTML or put it at the end of your HTML document before the closing body tag. 

This means that the browser can execute the DOM and parse the HTML to render the page and the user doesn’t have to wait for it to execute the scripts before the page renders.

And also always save your CSS as an external file so that the styling doesn’t have to load for every page.

Content Delivery Networks

Content delivery networks, are networks of servers that are used to distribute the load of delivering content.

Essentially, copies of your site are stored at multiple, geographically diverse data centers so that users have faster and more reliable access to your site.

Improve Server Response Time

What effects server response time?

Site traffic, resources used on each page, software that the server uses, hosting solution used, DNS lookup

How can we improve it?

Look for performance bottlenecks like slow database queries, slow routing, or a lack of adequate memory and fix them. The optimal server response time is under 200ms.

DNS Lookup

What is DNS Lookup

One of the biggest factors in how quickly your page loads is the amount of time your DNS lookup takes.

A DNS, or domain name system, is a server with a database of IP addresses and their associated hostnames. When a user types a URL into their browser, a DNS server is what translates that URL into the IP address that indicates its location online.

A DNS lookup, then, is the process of a finding a specific DNS record. You can think of it as your computer looking up a number in a phone book.

How do we improve it?

The amount of time this step takes depends on how fast your DNS provider is. If not, it may be time to switch to a faster DNS provider.

You can check out this DNS speed comparison report, which is updated monthly, to get an idea of where your provider compares to others

Minimise HTTP Requests

You can use Google Developer Tools to establish how many requests your site currently makes. From there you can reduce the requests by removing any unnecessary files. You can also combine your files for instance if you have multiple css files or multiple JS files you can combine them into one to reduce the http requests. Plug ins such as WP Rocket can make this process simple

Reduce Redirects

Some reasons for redirects:

  • To indicate the new location of a resource that has moved.
  • To reserve multiple domains, allow for “user-friendly” or “vanity” domains and URLs, and catch misspelled/mistyped URLs.
  • To add a trailing slash to URL directory names to make their contents accessible to the browser.

Why we need to reduce them:

  • Trigger additional http request cycles which slows down your page speed

How can we reduce them:

  • 301 permanent redirects – search engines will update their indexes so they don’t have to keep redirecting  

Testing Tools

Google Pagespeed Insights:

free tool from Google that runs a performance test on your site and provides recommendations on how to increase performance.


Has a number of useful features. It tracks your website’s performance history, makes data-driven recommendations on how to improve the website speed, and generates easy to understand reports.


Also provides recommendations on how to improve the performance of the page, draws statistics, and summarises all components.

Performance Budget Calculator:

Free tool that helps figure out what type of content you can use to keep your site running optimally.

More tools:

  • WebLOAD
  • LoadUI NG Pro
  • Tricentis Flood
  • LoadView
  • Apache JMeter
  • LoadRunner
  • Appvance
  • NeoLoad
  • LoadComplete
  • WAPT
  • Loadster
  • LoadImpact
  • Rational Performance Tester
  • Testing Anywhere









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