The Layman's Guide to Website Performance

You may have heard about website performance.

Google is talking about it, developers are talking about it, and big brands are talking about it. Website performance is increasing conversions and helping companies generate more revenue. It’s helping companies maintain a positive brand perception and earn repeat customers. It’s increasing website traffic and redefining what it means to have great customer service online.

But what, exactly, is website performance? And how does it apply to you? 

Let’s start by covering what performance is, and then – because of all the benefits listed above – we’ll talk about why you need to invest in improving yours. We’ll be talking about technical terms, but we’ll break them down into easy-to-understand concepts.

Learning this information and applying these strategies to your website is essential to succeeding online, because the internet is one is one of those places where “slow and steady wins the race” absolutely does not apply.

What is Website Performance?

When we talk about web performance, we’re simply talking about how quickly each page of a website loads into the user’s browser.

This means that a high-performing site is one that loads quickly so that a visitor can begin to see the content and interact with the site.

Website performance has become a concern because web pages have become more bloated with gigantic files that each visitor’s device is forced to download. Websites of the past were forced to be small because wireless networks were slower and less reliable.

Some may think that 4G networks and broadband are the norm, but 3G networks are still the most prevalent worldwide. So there’s still a limitation on how fast data can be transmitted, and if you put megabytes of data on your web pages, anyone who types in your web address will be forced to wait for your site to load.

Put another way, if your website doesn’t load quickly, then you’re forcing a potential customer, whose attention is already divided, to actually waste their time waiting for your website to appear.  And statistics show that people won’t tolerate that for very long.

In fact, 40% of people abandon websites that take longer than 3 seconds to load.

That number is staggering, and it should make you think seriously about what kind of revenue or website traffic your business is losing by not having great website performance.

Apart from losing traffic, you’re also losing credibility as a brand by being inconsiderate of customers’ time. 35% of people say they have a negative view of a brand if the company website doesn’t load quickly.

The homepage isn’t the only thing that needs to be fast. If a visitor gets into your site and tries to sign up for your enews or order a product, and that process is taking too long, people may give up trying. So performance has a huge impact on conversion rates, and if the conversion you want people to make generates revenue for your business, performance is important to your bottom line.

To take your first step towards having a high-performing website, you need to know just how fast or slow your site is.

Three Essential Metrics

There are multiple things happening between a user entering your web address and the website loading, so measuring performance can get tricky. There are lots of simple, generic online tools where you can plug in your web address, and it will spit out a score, but some of those scores aren’t a good benchmark of performance because they may focus on backend code details rather than the user experience.

At Aristotle, there are three essential metrics we use to measure performance. We chose these because if you score well in these metrics, you’re ensuring your website visitor has a great user experience.

Time to First Byte

When a user first types your web address onto their phone or computer, the browser sends a signal to the hosting server and requests the website data. Time to first byte (TTFB) refers to how long it takes for the hosting server to send the first byte of data back to the user’s device.

Page Weight

After the hosting server contacts the device, the website data begins to download. All the data – images, code, text, and videos – need to be transferred to the device. The more data there is to transfer, the more the web pages “weighs.”

Optimal Page Weight: 1500KB/1.5MB

Perceived Performance

The heavier the page weighs, and depending on connection speeds, the longer it takes the webpage to load. But not every single item on the page needs to load for the website to appearthat it has loaded. If above-the-fold content, meaning the initial elements at the top of the page, are loaded, then visitors can begin interacting; they will assume that the whole site is loaded. So perceived performance refers to the point when all the above-the-fold elements of the site load visually.

Optimal Perceived Performance: 2 seconds

Perceived performance is the only web performance factor that’s visible to everyone who comes to your site. The first two factors are something only your developer or analytics software can tell you. But if someone types in your web address and has to wait 10 seconds to begin interacting with your site? That’s a problem, and it’s one they’ll definitely notice.

Factors that Affect Performance

This section is where it gets a bit technical. Websites that appear to work effortlessly from the outside require detailed knowledge and technical experience to keep them running. To start fixing performance, we need to open the hood of your site and see what’s happening.

Images and File Sizes

Metrics affected: Page Weight, Perceived Performance

Of all things that affect load times, this is probably one of the biggest culprits in slowing down websites.

Did you check the last picture you uploaded to your site? Unless you optimized it for low file size, you’re probably looking at least a megabyte. That’s already two-thirds of the optimal page weight right there. And chances are good that you’ve got other images on that page, too.


Metrics affected: TTFB, Perceived Performance

Your website’s code has to be transferred from the server to the visitor’s device. The code elements are all different sizes and take different times to load.

Have you made sure that your resources are appropriately placed in your code to ensure the user gets some visual feedback on the screen as fast as possible?

Compression and Caching

Metrics Affected: TTFB, Perceived Performance

Caching is important, especially if you want visitors to return to your website. Using compression and caching will allow the site to load faster the second time, so that the browser does not need to transfer as much data and the perceived performance remains high.

Check out another post we did about the technical side of performance if you’ve got these basics covered.

Strategies for Improving Performance

We’ve talked about a lot of technical information here, but you shouldn’t think of web performance as daunting. Aristotle’s performance experts use the following best practices to ensure our clients’ websites are high-performing: 

Optimize images for good quality and small file size. There are new formats like WebP that are taking performance to the next level, but there are easier tricks like making sure your JPEGs are saved as Progressive files (not Baseline), which just means that the browser will first load a lower-quality version, and they progressively add detail to the image as the page loads more. This is extremely useful for perceived performance, especially when the image is small; a user won’t likely notice a slightly lower image quality on a phone, but they’ll definitely notice if a picture isn’t there.

Improve code compression, file grouping, or caching settings. Subpar file settings aren’t always obvious problems, and therefore they’re not always an obvious priority for web development teams, but the time it takes to load them will add up, and they will start to affect perceived performance.

Set a performance budget for your website. This means setting the measurements you want to hit on the three metrics we discussed above. It may be more work than you think to reduce your pageweight even close to 1,500KB. You may have to fudge that number a little. While the target numbers we provided are, of course, optimal, you need to start somewhere, and any improvement in performance means an increase in traffic retention and conversions.

Develop your own metrics for web performance. While the three we talked about are universal to all sites, your website also has unique goals to accomplish. You know what’s most important to your business, and you should make sure that gets prioritized. For instance, Twitter developed the TTFT metric – time to first tweet – because getting people to start reading tweets is the goal of Twitter’s website.

If you don’t have the time, knowledge, or staff to do these essential performance steps yourself, you can get expert consultation from our nationally-recognized performance experts. We can do a thorough analysis of your website, tell you where you have opportunities to get more traffic and conversions, and give strategic recommendations to improve your site. We can even implement those recommendations for you. Contact us to ask about a performance report.

Whether it’s prioritizing your visitor guide call-to-action or loading your image gallery quickly, you know what your goals are. Make them a priority for website performance, and they’ll help your business succeed online.