In this talk, I will walk through how I built the themevitals.com website which displays web performance data by Shopify theme populated with data from HTTP Archive and CrUX. In a similar talk for the 11ty meetup, I spoke more about the static website building process. In this talk, I will focus more on what data is available in HTTP Archive and CrUX and show this example of how I use it.
Content tagged “webperf”
See all tags or all content.
Announcing a new Shopify app to install SpeedCurve on your storefront, no developer required!
Published on SpeedCurve Blog
Here's how to install the SpeedCurve RUM app in your Shopify store, along with troubleshooting and next steps.
Published on SpeedCurve Blog
Today we have Sia Karamalegos joining us to talk about performance on the web. Sia is a freelance web developer, speaker, writer, teacher, tech community organizer and Google developer expert in web technologies.
Strategic web performance tips that you should be focusing on in 2025 to improve Core Web Vitals
On this bonus episode of Honest Ecommerce, we have Sia Karamalegos. She is a freelance developer and web performance engineer, a Google Developer Expert in web technologies, and formerly worked on the Shopify performance team. We talk about the difference between Lighthouse and Core Web Vitals, why site performance matters for bounce and conversion rates—not just SEO, how ThemeVitals collects and uses real-world data to benchmark Shopify themes, and how both merchants and theme developers can use it to make better performance decisions and so much more!
Building a site that shows real-user web performance data by Shopify theme using HTTP Archive, the Chrome User Experience Report, BigQuery, Node, and 11ty
Lighthouse 100 is a common goal for developers seeking to make their sites fast, but does this really center user experience? In this talk, I'll cover how to get a broader perspective on how real users are experiencing your website performance and better strategies for improving it.
In this informal talk, I will walk through how I built the themevitals.com website which displays web performance data by Shopify theme. It starts by processing monthly query data, then using that data to generate SVG charts on the server side. Then, 11ty builds all the pages, rendering the data and charts in a user-friendly and accessible way.
My most popular content in 2024 was all about the web - from performance to 11ty, hosting, and the Indie Web
See event link for details!
Lighthouse 100 is a common goal for developers seeking to make their sites fast, but does this really center user experience? In this talk, I'll cover how to get a broader perspective on how real users are experiencing your website performance and better strategies for improving it.
Learn the common causes for layout shift on Shopify Liquid storefronts and how to fix them
A smarter way to break down loading speed problems, identify causes, and implement optimizations
Considering headless? Why web performance should not be your only reason...
Published on Performance at Shopify
Default lazy loading for image tags and new section.index properties...
Published on Performance at Shopify
We see three common web performance problems related to layout position with Shopify themes...
Published on Performance at Shopify
What does this mean for Shopify sites and what can you do now to make sure you’re ready for the switch?
Published on Performance at Shopify
Before debugging FID and INP directly, look for low-hanging JavaScript fruit to trim out.
Published on Performance at Shopify
WebPageTest is an amazing tool for testing performance. Here's how to use the scripting feature to test sites behind passwords.
Published on Performance at Shopify
In this month’s “State of” event, we’re bringing you the State of Web Performance. We will be talking with Community members, library authors and maintainers to discuss community initiatives, how to identify Performance challenges, metrics to measure and resources to help you.
Does web performance truly matter? What are the reasons? Whether you're new to this topic or want to better understand the arguments, this article is for you.
Published on Performance at Shopify
Much like a carpenter or handyperson, every web performance expert has a set of their favorite tools. Here’s my own toolbox favorites and why.
Published on Planet Performance
Images are key to user experience. Making images smaller doesn't always result in better performance. How can images impact page load speed and layout shift?
Published on Performance at Shopify
103 Early Hints allow us to preconnect and even preload resources before the main document arrives. Come learn how the partnership between Shopify, Google, and Cloudflare led to this performance breakthrough, how Shopify is continuing to experiment with it at scale, and thoughts on what the future holds.
Get images right both on speed and quality, and your users will more likely convert.
In this month’s “State of” event, we’re bringing you the State of Web Performance. We will be talking with Community members, library authors and maintainers to discuss community initiatives, how to identify Performance challenges, metrics to measure and resources to help you.
Lazy loading is a performance strategy that de-prioritizes assets like images that are not needed immediately after a webpage is loaded. As with any strategy, you can misuse it causing worse performance.
Published on Performance at Shopify
At Shopify, we’ve seen what works and what doesn’t work when companies want to improve their web performance. We want to share with you our top learnings to get you on the path of success.
Published on Performance at Shopify
Sia Karamalegos joins the WebPageTest Live stream to talk about her research for this year's Web Almanac about the state of web performance.
The state of web performance in 2021 including the Core Web Vitals (LCP, CLS, FID) as well as FCP and TTFB for the top ~8M websites.
Published on Web Almanac by HTTP Archive
Let Cloudinary make your image management easier! In this talk, I'll show how to set up responsive images in Eleventy using Cloudinary and Eleventy shortcodes. If time permits, I'll also show how I generate social share images using Cloudinary and Eleventy.
What tools are web performance engineers using to measure site speed in 2021? Learn which are the most used tools as well as some new tools to try out.
Discover all JavaScript downloaded and used/unused for a site in a handy data visualization with Lighthouse Treemap.
Start using AVIF today with Cloudinary. Learn about your options, the tradeoffs, and how to overcome slow transformations.
My experiment with 30 days of web performance tips. All packaged up for your temporary viewing pleasure. Results from a Twitter series by Sia Karamalegos.
Is Lighthouse telling you to eliminate render-blocking resources? Learn what this means, why it's important, and how to fix it in your HTML, CSS, and JavaScript.
Use lite-youtube-embed in Eleventy for faster and more privacy-minded video
Learn the fundamentals behind responsive images and how to set them up in Eleventy using Cloudinary and Eleventy shortcodes
Fonts are lovely but can slow down our loads. How can we make them faster? We all love fonts. From Google Fonts to Typekit, Hoefler&Co and more, they give character and tone to our websites. The down side of fonts is that they can really slow down our loads. In this talk we'll learn about common pitfalls like critical requests depth and how to use resource hints to play tricks with latency to load web applications faster. We'll walk through a network profile to understand what's going on in the browser and how to make it faster.
What are some strategies for serving modern JavaScript to modern browsers?
Learn to optimize your images for the web in this video from PerfMatters Conf.
Web performance matters. From SEO to bottom-line revenue impacts, performance can make or break your app. However, fixing performance feels like a quagmire of expert-level topics. What if I told you JavaScript bundle sizes could be cut up to 50% by doing one thing only? Nearly 90% of web traffic runs on modern browsers, but we're transpiling all of our JavaScript to ES5. That’s expensive. In this talk, we'll learn about differential serving, or serving both modern bundles and legacy bundles using webpack. This talk is framework agnostic, and best if you have at least a basic understanding of JavaScript.
Images account for 50% of the bytes downloaded to load a website. How can you make sure that your users only download the smallest image necessary while preserving image quality? In this talk, we'll focus on the underlying concepts in HTML and CSS for serving responsive images, which you can take with you no matter which tool you use.Which file formats suit which image types best? How can you use art direction in images to show the best image for a viewport layout? Come learn about this and more!
Fonts are lovely but can slow down our loads. How can we make them faster? We all love fonts. From Google Fonts to Typekit, Hoefler&Co and more, they give character and tone to our websites. The down side of fonts is that they can really slow down our loads. In this talk we'll learn about common pitfalls like critical requests depth and how to use resource hints to play tricks with latency to load web applications faster. We'll walk through a network profile to understand what's going on in the browser and how to make it faster.
Trying to convince your company to make site load speed improvements? Maybe Google Analytics can help.
If you use Google Fonts, a few additional steps can lead to much faster load times. Learn about preconnect, optimal placement, font display, preload, and more in this post.
Help! My app bundle is 5MB! My users are angry that my app is so slow! It’s easy to forget that performance matters when we are under pressure to deliver features quickly. What data should we use to inform our decisions? From code splitting, lazy loading, and tree shaking to bundle analysis, progressive rendering, and modern transpiling, come learn how you can deliver a better experience to your users with high-performing front-end apps. This talk is library-agnostic (React, Angular, Vue, etc.).
App loading and run-time affect your bottom line. Fancy features aren’t worth anything if users leave the app out of frustration. Every second counts! React is super fast, but you could be shooting yourself in the foot with design decisions. Come learn how to make your React apps lightning fast! Page abandonment increases with every second of load time.Also, profiling and debugging performance issues can seem like an overwhelming topic to learn.In this session, we’ll cover the usual suspects of performance issues, from the basics of using the correct build, to the fundamentals of immutable data, to higher- level tools like Perf, shouldComponentUpdate, PureComponent, and memoizing computed props in Redux. We will both cover the concepts and walk through examples step- by - step so that by the end of this session you will feel like a React Speed Racer.You’ll get the most out of this session if you’re at least comfortable with React and ES6 syntax.
A strategic partner you can depend on
I make websites faster, smarter, and easier to grow.
If you want someone who’s creative and precise, deeply reliable, and not afraid to tell you what’s what to get you to the next level—I’m your partner.