Mastering Website Performance Speed Optimization: From Diagnosis to Results

Remember that time you visited a site you really wanted to read and it just didn’t load fast enough, if at all? Let me guess—you ended up hitting the back button in your browser within a couple of seconds because the page took so long to load. Yep, annoying. Especially when the content sounded really interesting.

If you remember feeling that annoyed or frustrated, imagine your website doing the same thing. 😬 Yikes. Why would you want to put your site visitors (i.e. your potential clients) through that only to have them jump ship and head to your competitor? And let's not forget that search engines penalize slow sites in their rankings.

Want to make sure your site performs well? Keep reading—that’s what you’ll learn more about in this article.

Why Website Speed Optimization Matters

The scenario at the beginning of this article reflected a critical part of a website: user experience. User Experience, or UX, in the context of websites, is how a person feels when visiting your site. When a website’s UX is done well, users can accomplish their goals effortlessly without being aware of the website itself. This idea is generally applied to visual design. But the technical side of a website, such as website speed, matters and influences UX too. A bad experience on your website may be forgotten eventually but it’ll be a lot harder to get that person back.

But it’s not just user experience that you need to be concerned with (though I’d argue it comes first). Google has made website speed a ranking signal though Core Web Vitals—their three key metrics that measure how fast and user-friendly your website is. When your website loads quickly, you’re not only providing a good user experience, you’re also signaling to Google (and other search engines) that your site deserves to rank higher (not that ranking is quite that simple—a discussion for another time).

This becomes even more critical when you consider mobile devices. More and more people use their phones and tablets as their primary, if not only, device to visit websites. While many people are fortunate to have good internet speeds, there are still many who don't. It’s not just about economies either. There are just some areas that don’t have good options for internet service providers and have to rely on cellular service. Slower internet or cellular speeds are a prime example of why your website’s performance matters—the faster and better optimized it is, the more people you’ll reach.

And that bit about hitting the back button in your browser when the page barely started loading? That’s a bounce. In website analytics terms, bounce rate is the percentage of visitors who leave your website after viewing only one page. The higher the percentage,  the more visitors are leaving without engaging with your content. Slow loading speeds are one of the biggest causes of high bounce rates.

When you step back and start to put these concepts together, you can start to see a domino effect and the business impact becomes clear: faster sites rank better, better rankings bring more traffic, more traffic creates more opportunities for sales. Can you see how speed optimization can become a path to revenue growth?

Understanding Performance Metrics

Now that you can see the bigger picture you might be motivated to test and fix any speed issues on your website. But before you can do that, you need to know what you’re measuring.

The three key metrics to track (i.e. Core Web Vitals):

1. LCP - Largest Contentful Paint: Measures how long it takes for the largest visible element on your page to load (usually the main image or text block)
2. FID - First Input Delay: Measures how long it takes for your page to respond when a user first tries to interact with it (clicking a button, link, etc.)
3. CLS - Cumulative Layout Shift: Measures how much your page elements move around while loading (like when text suddenly jumps because an image loads late)

Or in simpler terms:

• LCP = loading speed
• FID = interactivity speed
• CLS = visual stability

These three metrics together give you (and Google) a picture of the real user experience on your site.

So how do you determine how your website fares? There are three tools I recommend:

• PageSpeed Insights (easy scores + recommendations)
• GTmetrix (good balance of detail and usability)
• WebPageTest (most detailed technical analysis)

Each tool serves different needs depending on your technical comfort level and what specific insights you're looking for.

PageSpeed Insights

Pros:

• Direct from Google, so it reflects what they actually care about for rankings
• Provides specific, actionable recommendations with priority levels
• It’s free

Cons:

• You can't choose which location to test from which can be important depending on your audience
• It sometimes gives vague recommendations without clear implementation steps
• Because it focuses so heavily on Google's priorities, it can miss other performance issues

GTmetrix

Pros:

• Good balance of technical detail and easy-to-understand metrics
• Allows testing from different global locations
• Provides historical tracking to monitor improvements over time

Cons:

• Their free version limits testing frequency and locations
• Can be overwhelming for non-technical users with too much data
• Some advanced features require paid subscription

WebPageTest

Pros:

• It has the most comprehensive technical analysis with waterfall charts and filmstrip views
• Extensive customization options (browsers, connection speeds, locations)
• Provides detailed technical data that other free tools don't offer

Cons:

• Steep learning curve which can be intimidating for beginners
• So much data it's easy to get lost in details rather than taking action
• Free tier has usage limits

I’ve used all three for various reasons, even on the same project. If you’re just curious or can’t hire a website optimization professional to help you with this just yet, go with Google PageSpeed Insights.

Whether you hire a developer to help you with performance optimization or want to give it a go yourself, don’t try to fix everything all at once and make sure you’re setting realistic goals:

1. Start with baseline measurements. You can't improve what you don't measure, and you need to know where you're starting from. Test your current site speed (i.e. before making any changes) across all three tools first. And be sure to document your existing Core Web Vitals score as your starting point.
2. Focus on mobile first. For a lot of websites, most traffic is mobile, so it’s a good idea to prioritize mobile performance goals. The positive side effect of this is that desktop (i.e. non-mobile) performance will often improve.
3. Set tiered goals. Aim for "good" thresholds first, then work your way toward "excellent". Focus on the biggest impact wins before tackling the minor optimizations. And consider setting 3, 6, and 12 month targets rather than expecting overnight results. This keeps you from getting overwhelmed and ensures you're making steady progress.
4. Balance performance with functionality. Don’t sacrifice essential features for speed score and consider which third-party tools (which often negatively impact performance) are truly necessary versus nice to have. This prevents you from optimizing yourself into a site that doesn't serve your business goals.
5. Consider your industry and audience. Research what’s typical for your industry and factor in your audience’s typical internet speeds and devices. A local service business will likely have different needs than a national one.

That said, remember that a slightly slower site that converts well beats a lightning-fast site that doesn't meet user needs.

Essential Website Performance Speed Optimization Techniques

In my experience there are three areas that most sites can improve in to get quick speed optimization wins: image optimization, code optimization, and server considerations.

A lot of websites have images that are far too large either in dimensions (even if they’re shown smaller) or file size, or worse, both. This is an instant performance killer. To get an immediate win, make sure you’re using smaller file sizes (a good CMS will do this for you) and use modern formats like WebP or AVIF. These formats are compressed more than your typical JPG or PNG without losing much, if any, quality. Combine that with using responsive image techniques and lazy loading and you’re going to be well ahead of many websites.

Optimizing your code is your next step after images, but it can take longer depending on your approach and knowledge of the platform or CMS your website is on. For starters, minifying your CSS and JavaScript files can improve performance right off the bat. To push that further, try not to have more than a couple CSS and JavaScript files per page to begin with.

And finally, take a good look at the server your website is hosted on. Sometimes folks just pick the wrong hosting service for their website. (Want to know how to pick a good hosting option? Read my article, "The Business Owner's Guide to Website Hosting".) If you’re on a good hosting setup then you might look into Content Delivery Networks (CDNs) for your assets (e.g. images, videos, etc.) and caching strategies.

Common Performance Killers to Avoid

As mentioned in the previous section, having oversized images is a common performance killer and should be avoided. But videos can be an even bigger killer if they’re not hosted on a third party platform like YouTube, Vimeo, Wistia, etc.

Similarly, having too many images or videos can put a strain on your site’s speed. Same with having a lot of CSS or JavaScript files, which some CMS platforms or their plugins do by default (looking at you, WordPress). Why is this a strain? Because each image, video, CSS, and JavaScript file requires your web browser to make what’s called an HTTP request. An HTTP request is like asking someone to bring you something. Every time your browser needs a file from a website—whether it's an image, a video, or a CSS or JavaScript file—it has to make a separate "request" to the server to get it. When you visit a webpage, your browser might make 50+ separate requests—one for the HTML, one for each image, one for the CSS styling, one for each JavaScript file, etc. The more requests needed, the longer the page takes to load.

In a similar manner, there are times when files cause your website to load slower. These are called render-blocking resources. They’re like a traffic jam that stops everything behind it. When your browser encounters certain files (usually CSS and JavaScript), it has to stop and fully process them before it can continue showing the rest of the page. So what ends up happening is that visitors see a blank screen or partially loaded page while they wait. Not great for UX.

Testing and Monitoring Your Results

After implementing speed optimizations, you'll want to verify that your changes actually made a difference. This is where those baseline measurements you took earlier become crucial—you need something to compare against.

Important note: don’t test immediately after making changes. Wait at least 24-48 hours before running new tests, especially if you've implemented caching or CDN changes. These systems need time to propagate and stabilize.

When you’re ready to test, start by running the same tests you did initially using the same tools and test locations. Document the improvements to your Core Web Vitals scores and overall page load times. Don't be surprised if some metrics improve more than others—that's normal!

Oh, and don't just test your homepage. Check key landing pages, your most popular blog posts, and any pages that are crucial to your business goals. Performance can vary significantly across different page types.

Although not vital, consider setting up automated monitoring so you'll know if performance degrades over time. This is especially important if multiple people can add content to your site—it's easy for new images or plugins to undo your optimization work.

And of course, pay attention to your analytics after optimization. Are you seeing improvements in bounce rate, time on page, or conversion rates? These business metrics matter much more than the technical scores.

Your Next Steps in Speed Optimization

Website performance speed optimization isn't just about making your site faster—it's about creating a better experience for your visitors while improving your search rankings and business results. I’d argue that UX is the main reason that performance optimization is important. The good news is that you don't need to tackle everything at once.

Start with the quick wins: optimize your images, clean up unnecessary files, and ensure you're on solid hosting. These changes alone can make a dramatic difference in how your site performs. From there, you can dive deeper into more advanced techniques as needed.

Remember, the goal isn't to achieve perfect scores in every performance tool. The goal is to create a website that loads quickly enough that your visitors can focus on your content and services rather than waiting for pages to load.

If this feels overwhelming or you'd rather focus on running your business while someone else handles the technical details, that's exactly the kind of project I help businesses with. Feel free to get in touch to discuss how we can improve your website's performance together.