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Website Performance Explained

Website Performance Explained

Website performance is the speed and availability of your website. Speed refers to how fast your site can be loaded when a request is made from a web browser. Availability can also be referred to as uptime or reliability and refers to the percentage of time that your site can be accessed.

Note: This is part 1 of our website performance guide. For readers looking for actionable tips to improve their site's performance, read: 10 tips to speed up your website.

Why Does Your Website Performance Matter



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Website speed is essential because it makes customers happy and helps websites rank higher in search engines. While that’s the two cents version, it’s the essence of understanding why you need to improve your website performance.

You don't want to wait around when you're on the web; nobody does. Page speed is crucial since it also affects conversion rates and brand perception. So when your web pages take too long to load up, everyone drops them in priority. Potential visitors will simply close the tab and go somewhere else.

While there are many areas of the website you can focus on to improve speed, we can categorize them broadly to target four key areas.

Each targeted area will significantly benefit your website traffic if you improve performance.

Rank Higher on Search Engine

Many factors will affect where your site appears on Search Engine Results Pages. One of the most critical factors is page load time. How fast or slow page loads are can significantly impact whether a viewer will continue to access your site or move on to another one.

Google's algorithm has always measured and ranked websites based on dozens of criteria. In 2010, Google added page speed to its list of factors determining Search Engine Results Page (SERP) rankings. 

Loading time has become such an important factor that Google created PageSpeed Insights, which allows you to measure how well your website performs in terms of speed and recommends fixes for any issues.

While there's no way we can gauge the extent of page speed impact on SEO, the fact it is involved is confirmed. What better way of knowing than directly from the horse's mouth?

Case Study: Google Comments on Site Speed in Web Search Ranking

Website page load speed is a google ranking factor
Google clearly highlights why site speed is important and it's a part of their ranking algorithms.

Google wants a faster web for many reasons. The company understands that slow websites displease visitors. In addition, faster websites can even reduce operational costs. Because of these reasons, Google places great emphasis on website speed when determining your search rankings

Improve User Experience

If you’ve ever sat in front of your computer getting increasingly angrier at a website that crawls, you’ll understand the impact of website speed on the user experience. The average attention span for adults is eight seconds, which is one second shorter than it was in 2000 and four seconds shorter than the attention span of a goldfish. 

If your website takes more than two to three seconds to load, you're losing out on valuable traffic and potential customers. According to web experts Bitcatcha, website speed is your first opportunity to impress visitors. Slow websites will agitate them, negatively impacting their impression of your website or business. 

Web pages that fail to load within two seconds are likely to pass on a poor user experience. Unhappy users are also less likely to trust your content or make a purchase on your website.

Case Study: Better Speeds Helped Vodafone Increase Sales by 8%

The table shows the value for DOMContentLoaded (DCL ) and Largest Content Paint (LCP) that Vodafone observed during the test.
The table shows the value for DOMContentLoaded (DCL ) and Largest Content Paint (LCP) that Vodafone observed during the test.

We already know that faster page speeds are better. However, you can work on many areas that affect speed. We can see this demonstrated in the case of Vodafone. With a 31% improvement in Largest Content Paint (LCP) times, it increased sales by 8%.

Since it’s a large company, Vodafone couldn’t arbitrarily make changes without knowing clear results. Because of that, it ran an A/B test of two versions of a landing page. A focus on LCP resulted in better sales and increased cart-to-visit rates throughout the experiment.

Better Site's Bounce Rate

The bounce rate of your website is a critical indicator of your site's quality. It's a percentage (or ratio) that tells you how many people leave your site after viewing only one page versus how many people are clicking through and visiting multiple pages. 

For example, if your web page has a bounce rate of 50%, half of the visitors to that web page left without visiting any other pages on your site. While many things can affect bounce rate, you may be surprised that website speed is one major factor.

By decreasing the time your web page takes to load, you can significantly improve your site's bounce rate.

Case Study: Google Found Longer Load Times Significantly Increase Bounce Rates

The result shows the new industry benchmarks for mobile page speed.
The result shows the new industry benchmarks for mobile page speed.

Google is one of the top supporters of a faster web. They originally ran an experiment in 2017 (now updated) that found slower web pages experienced a 123% higher bounce rate. The percentage varies depending on the time taken for the page to load.

The experiment was fascinating since Google ran it on a deep neural network. That enabled the test to mimic human experience with the website, providing a more realistic test result. The search giant reiterated the need to build websites optimized for mobile devices.

Increase Conversion Rates

Conversion is the process of turning random website visitors into paying customers. But have you ever stopped to think about how your website speed affects that conversion rate? Well, it's something you should think about—and perhaps even worry about.

With this said, there is no ideal loading time for websites because the optimal speed depends on the type of site that you have. If you have a content-based website where people come for information, you can afford to have slightly longer loading times than an eCommerce site where people try to make purchases as quickly as possible.

Still, running a few tests should clearly show you some differences in how your website speed affects your conversion rates.

Case Study: Pinterest Boosted Mobile Conversions by 60%

In 2015, Pinterest ran an experiment that improved the performance of its landing page on mobile by 60%. The increase in performance on this platform led to 40% more conversions on mobile devices.

Their optimizations looked at the front end, back end, and network areas. The ultimate goal was to reduce overhead, improve performance via optimized processing, and streamline data flow. The adjustments made were granular, resulting in graduate but tangible metric improvements.

7 Factors that Affect Your Website's Performance

A website is built out of many moving parts; images, code, and even external resources at times. All these things add to the overall ‘weight’ of a website. Consider this; a website made up of only text will load much faster than one with a lot of images.

Of course, that is an extreme comparison, but it serves to outline how various things affect our website performance. To have your website perform optimally, strike a balance of form versus functionality to see what works best for you. 

1. Caching

Caching is the holding of data in memory to increase performance. Web applications can keep high-priority data in memory so that it can be processed more quickly. The data held in memory acts as a ‘snapshot’ of a website which can be served quickly upon request.

There are two main types of caching when it comes to websites – Server Side Caching and Client Side Caching.

How web caching works
How Web Caching works (source: Kinsta).

What is Server Side Caching?

Server side caching makes use of the memory available on the web server. The most common forms of server side caching are database and object caching. This helps web applications which are heavily database-reliant (such as WordPress) to reduce potential load on both the database and processor. Other forms of server side caching include; opcode cache, page cache, proxy server cache, and CDN cache.

What is Client Side Caching?

Client side caching makes use of memory on the user’s side of the equation. There are various types of client side caching, the most popular / common form of which is browser request caching which is used to limit or manage how often the browser requests updated files from the web server.

2. DNS Lookup

Your website DNS resolving time affect site speed
Your website DNS resolving time varies depending on provider.

Although there isn’t much you can do to directly influence your server response speed, there is one element of it you can improve on. DNS Lookup is one of the elements that make up server response speed.

Different DNS providers have different levels of performance. For example, if you use Cloudflare as your DNS provider, you can expect much better performance as compared to if you were using GoDaddy.

By changing your DNS provider and opting for a faster performing one you can shave valuable time off your server response speed. In some cases the difference can be as much as over 120ms, which is significant.

3. Multimedia

example of large image
A bright, vibrant image may do wonders for your site but could increase loading time significantly.

Images and video are usually much larger in size than code or plain text. A single page of plain text could take up as little as 4KB of space. A full-page image is more likely to take up 80KB to 100KB even if properly optimized.

4. External Resources

If your site is using the services provided by a third-party it may increase latency. This is because when loading your site, the server must spend additional time communicating with yet another server to load the service from that site to yours.

As an example of this, let’s consider a popular web statistics service called StatCounter. In the image above, ignore everything in between and focus on the final line. In this case, using StatCounter on this site adds almost an entire second to the loading time of this site.

5. Website Functions

WordPress is a content management system (CMS) that powers more than 30% of all websites on the Internet today. It is easy to use and highly modular, allowing user to substitute coding knowledge with what it calls plugins.

However, WordPress is open source, which means that anyone can contribute to the plugin pool. This includes both professional developers as well as amateurs trying their hand out at coding. The result is a pool of plugins that varies greatly in quality.

Even websites that aren’t run on WordPress can fall prey to ‘plugin syndrome’ as they use third-party add-ons to enhance their sites. Using an overabundance of plugins can slow down your site significantly and expose it to greater security risks.

6. Server Location

Test site hosted in the United States East Coast - Notice how physical distance affects web server response time. The closer your web host is to your targeted traffic, the faster your website loads.
Test site hosted in the United States East Coast – Notice how physical distance affects web server response time. The closer your web host is to your targeted traffic, the faster your website loads.

Aside from how well your site and server performs another thing that affects how your site works with visitors is how far it is located form your target market. If you’re targeting international traffic, there isn’t much you can do about this. However, if your target traffic is more localized then your choice of server location can make a difference.

Take for example if you were running a website that targeted on visitors from the Asia region. In this scenario, it would help if your web host had a data center in that region. The closer your web host is to your targeted traffic, the lower the latency will be for your visitors.

7. Limited Resources

All web hosting plans come with pre-defined amounts of resources which you can use. Some of the resources which will have an affect on the performance of your site include CPU time and amount of memory.

If your site is constantly using or exceeding the amount of resources allocated to it issues may arise. Having insufficient resources can lead to slowdowns or even account suspensions. Remember that with most plans, you are sharing resources with many other users. If either you or they are constantly maximizing resource usage the entire system may suffer from poor performance.

Testing Your Website Performance

Your Server Performance is Not Website Performance

It is important to realize that there is a distinct difference between server performance and website performance. Server performance is how quickly a server is able to respond to a request. Website performance is how much time it takes for a website or webpage to load.

  "Server Speed" and "Availability" are the two server performance data we collect at our sister site HostScore.
“Server Speed” and “Availability” are the two server performance data we collect at our sister site HostScore.

Server Performance

Server Performance is a small part of website performance since it contributes to the overall load time. It is highly dependent upon the quality of the equipment and infrastructure that the web hosting company you choose has.

Website Performance

Website performance is made up of many other factors, many of which can be fine-tuned by you as the site administrator. Things that can be tweaked to improve your overall website performance include caching, script optimization, latency, compression, and more.

Tools to Test Your Website Speed Performance

Now that you know what some of the key areas that affect your website performance, let’s consider how you can monitor the various aspects of things. There are a ton of free tools available which you can use to gauge how well your website is performing.

WebPage Test – This service helps your micro-analyze the performance of your website from specific geographic locations. All you need to do is to type in your website address and select which server you wish to conduct the test.

BitCatcha – For those who might be focusing on just server response time, you can try the BitCatcha Server Speed Checker. This convenient tool lets you test your site’s response from various locations strategically located around the globe – all at once.

GTmetrix – Another popular tool that helps you test page speed is GTmetrix. This not only helps you analyze your performance details but provides some highlights as to what areas can be improved as well. Think of it as something like Webpage Test with suggestions.

For a complete list, check out our List of Website Speed Test Tools.

Next: How to Improve Your Website Performance?

Web performance is something that is vital to the survival of all websites. Slow sites frustrate users and may also be an indication that something is wrong, such as over usage of resources or incorrect configurations. 

Rather than wait for problems to occur, testing your site and making sure that it is working correctly and within specifications is always a good idea. Here are 10 ways you can improve your website performance.

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Article by Jerry Low

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