"Should I use synthetic monitoring, real user monitoring, or CrUX?" We hear this question a lot. It's important to know the strengths and limitations of each monitoring tool and what they’re best used for, so we don’t miss out on valuable insights.This post includes:How synthetic and real user monitoring (RUM) workWhat is CrUX?Is CrUX a substitute for RUM?When and why to use each tool An obscure cheese metaphorPlus a quick survey question at the end!Synthetic and real user monitoringFor the longest time, there have been two primary forms of front-end web performance data.Synthetic data (sometimes called lab data) is performance data collected based on a very specific set of variables. For example, you can choose to test your product page on a 3G network, from Italy, on a Chrome desktop browser.Real user data (sometimes called field data) is performance data collected from real users as they browse your site under a wide variety of contexts (different browsers, devices, connection speed

What's the point of a performance metric that doesn't align with user behavior – and ultimately business outcomes? Looking at four different retail sites, we compared each LoAF metric for desktop and mobile and correlated it to conversion rate. We saw some surprising trends alongside some expected patterns.We recently shipped support for Long Animation Frames (LoAF). We're buzzing with excitement about having better diagnostic capabilities, including script attribution for INP and our new experimental metric, Total Blocking Duration (TBD).While Andy has gone deep in the weeds on LoAF, in this post let's put the new set of metrics to the test and see how well they reflect the user experience. We'll look at real-world data from real websites and find an answer to the question: How do Long Animation Frames affect user behavior?First, what is a Long Animation Frame?We've covered Long Animation Frames (LoAFs) extensively in a couple of recent posts:The Definitive Guide to Long Animation Fra

This month's performance hero is someone who's helped some of the biggest brands in the world speed up their sites – and who generously shares his wealth of experience with the performance community through articles, videos, and conference talks. Thank you for everything you do, Harry Roberts!What we love about Harry is that he's both an idealist who believes in delivering great user experiences, and a pragmatist who knows how to measure the impact of site speed on businesses. Harry and I recently had what we jokingly called a fireside chat. As a SpeedCurve power user with his clients, Harry had a lot of great feedback and insights into how he uses our tools. But our conversation was actually much broader, so I thought a lot of folks might be interested to hear Harry's thoughts about performance in general. I also thought it would be great to give him long-overdue kudos as this month's Performance Hero!Keep scrolling to watch the video of our chat and hear why Harry had the following t

We've made a major update to how you create, manage, and monitor performance budgets in SpeedCurve – and we think you're going to love it.Until now, performance budgets lived inside your Favorites dashboards. That worked well for surfacing budget charts in context with the rest of your performance data, but it made managing budgets frustrating because they were spread all over your Favorites dashboards.To fix this issue, we've moved performance budget management into its own dedicated Budgets dashboard. This change unlocks powerful new capabilities and makes tracking your performance thresholds and goals easier and more intuitive than ever.Centralized budget managementPerformance budgets now live in their own dedicated dashboard. This gives you a single, central place to view, manage, and monitor your budgets without having to navigate through multiple Favorites dashboards.Easier navigation and filteringWe’ve introduced both a list view and the familiar card view, so you can choose the

Now you can integrate robust real user monitoring into your Magento project in minutes!As a product manager, I have to say there are few things more flattering than having our users build apps that empower other folks to use our product.Hot on the heels of our SpeedCurve RUM for Shopify app is a new open‑source Magento module – from Jesper Ingels and the awesome team at Bluebird Day – that lets you integrate SpeedCurve real user monitoring into your Magento project in minutes – no coding required!Keep reading to learn the benefits of gathering real user data and how to get started.The SpeedCurve Magento 2 module is designed for standard Magento 2 front-end themes (Luma-based or custom themes using Layout XML, RequireJS, etc.).With this module, you can:Enter your SpeedCurve RUM ID (available on your Settings page) and the RUM script loads automatically on your pagesConfigure all settings via the Magento Admin Panel, including RUM ID, page labels, and cookie consent handling.Manage page

SpeedCurve now has a Shopify app to make installing and using SpeedCurve in your Shopify store much easier. With this app, you can quickly set up real user monitoring – no coding required. Here's how to install the SpeedCurve RUM app in your Shopify store, along with troubleshooting and next steps.In ecommerce, speed isn’t just nice to have – it’s a competitive advantage. Slow websites lead to frustrated users, lost sales, and damaged brand trust. With the SpeedCurve RUM app for Shopify, you can track metrics like Core Web Vitals, identify performance issues, measure the impact of site speed on conversion rates, and stay ahead of page slowdowns – no coding required.How to install and use SpeedCurve RUM1. Create your SpeedCurve accountIf you don't already have an account, it's easy to create a free 30-day trial. (No credit card required!) 2. Install the SpeedCurve RUM Shopify app If you haven't yet done this, install the SpeedCurve Shopify app.3. Connect the Shopify app to your SpeedCur

If you run a Shopify store, you already know how critical it is to provide a seamless shopping experience. That's why I was so excited when the folks at SpeedCurve asked me to draw on my Shopify experience to build their new RUM app for Shopify storefronts. Now I'm here to let you know how it works and why it's an important part of your UX toolset.In ecommerce, speed isn’t just nice to have – it’s a competitive advantage. Slow websites lead to frustrated users, lost sales, and damaged brand trust.With the SpeedCurve RUM app, you can track metrics like Core Web Vitals, identify performance issues, measure the impact of site speed on conversion rates, and stay ahead of page slowdowns – no coding required.> How to enable SpeedCurve RUM in your Shopify storeSite speed is critical in ecommerceBefore we dig into the new SpeedCurve RUM details, let’s cover why front-end web performance is so important for online stores.Poor performance increases bounce rateShoppers are impatient. A delay of j

With Long Animation Frames (commonly referred to as LoAF, pronounced 'LO-aff') we finally have a way to understand the impact of our code on our visitors' experiences.Long Animation Frame – a frame that took longer then 50ms from its start to when it started paintingLoAF allows us to understand how scripts and other tasks affect both hard and soft navigations, as well as how scripts affect interactions. Using the data LoAF provides, we can identify problem scripts and target changes that improve our visitors' experience. We can also finally start to quantify the impact of third-party scripts as they execute in our visitors' browsers.Keep reading to learn:Why animation frame rate mattersAnatomy of a Long Animation FrameKey LoAF milestones and what we can do with milestone dataScript attribution (and why script details might sometimes be unavailable)How to match script data to Interaction to Next Paint, including sub-partsHow to capture LoAF entriesGetting started with LoAFLoAF support i

CPU consumption by the browser is one of the main causes – if not the number one cause – of a poor user experience. The primary culprit? JavaScript execution. Now you can use SpeedCurve to monitor Long Animation Frames (LoAFs) and fix the third parties and other scripts that are hurting your page speed.Until recently, we've had little evidence from the field that definitively attributes the root cause of rendering delays. While JavaScript Long Tasks gave us a good indication that there were blocking tasks affecting metrics such as Interaction to Next Paint and Largest Contentful Paint, there was no way to attribute the work or understand how it was ultimately affecting rendering. Fortunately, we've gotten a lot of help from Chrome in improving the attribution – and ultimately the actionability – of the data we collect in the field with RUM. The introduction of the Long Animation Frames API (LoAF) not only gives us better methods for understanding what's happening on the browser's main

Have you ever wondered why your site got faster, but your business and user engagement metrics didn't improve? The answer might lie on the performance plateau.Have you ever asked yourself these questions?"I made my pages faster, but my business and user engagement metrics didn't change. WHY???""How do I know how fast my site should be?""How can I demonstrate the business value of page speed to people in my organization?"The answers might lie with identifying and understanding the performance plateau for your site.What is the "performance plateau"?The performance plateau is the point at which changes to your website’s rendering metrics (such as Start Render and Largest Contentful Paint) cease to matter because you’ve bottomed out in terms of business and user engagement metrics.In other words, if your page speed metrics are on the performance plateau, making them a couple of seconds faster probably won't help your business.A correlation chart is an essential tool for identifying your pe