For those who don’t remember the 90s, here are the kinds of memories that sound dredges up:

• Opening a website with an image and watching it load raster line by raster line.
• Admonishing everyone else in the house not to pick up the phone while you grab a snack from the fridge.
• Sitting back down and realizing the site still. Hasn’t. Loaded.

Things aren’t that bad anymore, but this not-so-distant past demonstrates why slow page performance is bad for users. And what’s bad for users is bad for your web presence.

In short — a slow website costs your company in visibility, reputation, traffic, leads, and revenue. 

Fortunately, there are easy-to-use tools and tips to help you rate your website’s speed, diagnose the issue, and solve whatever is throttling your site.

Let’s take a closer look. 

Why site speed matters

Site speed matters for just about every important web performance metric — from page views to bounce rates to conversions. 

By tracking 30 million user sessions on 37 websites over the course of a month, Deloitte found that improving site speed by just one-tenth of a second increased page views by 5.2%, raised conversion rates by 8.4%, and for ecommerce sites, grew the average order value by 9.2%. For context, it takes about one-third of a second for a human to blink.

Shoot for a PageSpeed Insights score of 90+ 

According to Google, a score above 90 is considered good. Anything below that likely needs improvement to avoid the risk of lower rankings in the Google search results.

Google wants to reward websites with a positive user experience. Speed is just one component of that because slow websites are frustrating for users to visit and interact with.

Just as slow websites can rank well on Google if they’re mastering the other areas of search engine optimization (SEO), lightning fast websites can rank poorly if they fail other measures of a positive user experience. 

Deliver a positive user experience by making sure your content is helpful, thorough and reputable. Google measures this specifically through metrics like backlinks, internal links, relevant headings, body copy and image tags.

In short — make sure you’re at the top of your SEO game before focusing on site speed. Site speed isn’t the only thing Google looks at for ranking, but it does contribute to the overall user experience on both desktop and mobile. 

6 ways site speed is measured

Though there are many ways to measure website load speed, let’s focus on the ones that affect the user experience the most. 

First contentful paint

First contentful paint (FCP) measures how long it takes from when your page starts to load to when visitors can see the first-loaded content  — like text, images, or video —- on their screen. 

This doesn’t mean all the content is loaded, but it helps your visitors feel like your page has loaded faster, making for a better user experience.

Largest contentful paint

Largest contentful paint (LCP) gauges how long it takes before visitors can see the largest content on the page. This is often something like a header image or a video that has a large file size.

Research has shown that the sooner that piece of content loads, the happier users are. According to Google, you should aim for 2.5 seconds or less. For every 100 milliseconds faster that content loads, there is a drop in bounce rate and rise in conversion rates. 

Speed index

Speed index shows the time it takes for visitors to see everything “above the fold,” or all the content available without having to scroll or interact with the page.

Google encourages website owners to keep this number under 3,000 milliseconds. Like FCP, Google sees this as an important metric because it gives the impression to users that the page is fully loaded. Since the most relevant parts of a page page are likely above the fold, speed index also helps you gauge how quickly users can access the most important information of your site. 

Time to interactive

Visitors don’t want to just look at your page. They want to do something with it — whether that’s scrolling, pressing play on a video, clicking a link, or entering their information into a data field.

You don’t want visitors to be able to see a video, or other interactive element for example, and not be able to use it.

Time to interactive (TTI) measures how long it takes for your page to be fully interactive. Google considers a fast time to interactive speed to be 3.8 seconds.

Total blocking time

Total blocking time (TBT) measures how much “long tasks” are contributing toward your TTI metric.

These long tasks, or things that take your website longer than 50 milliseconds to load, can extend the amount of time where your website looks usable (after the first contentful paint) and when it is usable (TTI). This can lead to frustrated users because they try to interact with your website but get no response.

Your TBT should be 200 milliseconds or less to reduce the amount of time your website isn’t responsive as it loads. An unresponsive web page frustrates your visitors and can lead them to bounce. 

Cumulative layout shift

That aggravating experience of trying to click the little X to close an ad, only to have the ad move as more content loads on the page, is called cumulative layout shift (CLS).

These shifts undercut the user experience and hurt your score because those shifts cause accidental clicks, which lead to a poor user experience. A case study of Yahoo! Japan’s news page showed this principle in action. For every 0.2 seconds they reduced the time that shift happened, they saw a 15.1% increase in the number of pages a visitor looked at during their session.

Here’s how to improve your site speed score

Just because you have a sub-90 site speed score doesn’t mean you're doomed to a low page ranking forever. You can make choices in both the design of your website and the content you include on its pages to improve that score.

The first step is to see where your website stands now by performing a website speed test. Put your website URL into the tool and wait while the tool analyzes your website. You’ll end up with a dashboard of metrics like FCP, LCP, and speed index listed for both the desktop and mobile version of your website. People in the US are more likely to access the internet through their mobile device, so if you need to prioritize which version of your site to focus on, it might be wise to start by making sure your site performs well on mobile.

Each of the metrics your site speed tool measured will be highlighted with a color based on your site’s performance in that category. Metrics highlighted in green indicate that your website performed well. If the metric is yellow, you know it needs improvement. The metrics in red denote areas where your site is performing poorly enough to hurt your user experience and your standing on search pages. This dashboard serves as a priority list for improving your website. Start with the metrics that are marked in red before you worry about improving metrics marked in yellow.

Your dashboard of results will offer suggestions about how to start improving each metric to help get start improving your speed. In the example below, PageSpeed Insights identified CSS stylesheets that are not being used and plugins that are loading too slowly.

Some of the common suggestions PageSpeed Insights will make for improving your website include:

• Image optimization: Images are resource hogs. Compress your images using modern formats like WebP to trim 25% of the fat from your images without any loss in quality compared to .png and .jpeg files.
  
  
• Browser caching: Save time for returning visitors by enabling browsers to store things locally like style sheets, JavaScript code, and images.
  The next time that same visitor arrives on the web page, their browser will already have that information stored. The browser won’t have to download the information from the website’s server, which reduces the page load time.
  
  
• Minimizing JavaScript and CSS stylesheets:  Strip comments, spaces, and unnecessary code from your JavaScript and CSS files with free tools like Minifier. The less extraneous information you have in your code, the faster it loads.
  
  
• Removing unnecessary code and plugins: The longer you have your website, the more likely you are to end up with too many redirects, extra tools and information you aren’t using anymore. That could be because you changed how your website looks or operates. Or you found a new tool that works better than what you used before but forgot to delete the outdated tool.

Make it a point to regularly look through your website to make sure it’s not carrying around excess weight in the form of too many lines of code, outdated stylesheets, and large images.

Site speed is an important ranking factor, but it’s only the beginning

Optimizing your website is an important component of ranking well on search engines. Once you have those technical aspects figured out, it’s time to mix a little art and creativity into the science of SEO.

Learn more about SEO and how to optimize your site with our SEO essential guide.