Skip to content

Speed Matters

Skater shapes

Test agent updates: Chrome 91, Lighthouse 7.5

Updated test agents are being rolled out to all regions today. They include updates to several pieces of core software, including:

  • Chrome has been updated from version 89 to 91
  • Lighthouse has been updated from version 7.3.0 to 7.5.0

New features: Chrome Beta and Canary support & LCP element highlighting

Today's release includes a some great new features:

  • Support for both Chrome beta and canary test agents
  • LCP element highlighting and new key rendering visuals

    For more information on these features, see our latest post.

  • LUX update: lux.js v214

    We have released v214 of lux.js. This is a hotfix release that reverts the long task buffering introduced in v213 due to a bug in the buffering implementation.

    LUX update: lux.js v213

    We have released v213 of lux.js. This release contains bug fixes and other improvements:

    • Long tasks are now buffered, enabling LUX to instrument long tasks that occurred before the snippet.
    • User interaction times in a SPA are now relative to the most recent LUX.init call, rather than relative to navigationStart.
    • Element identifiers for user interaction (click, keypress) have been improved. Buttons and links that don't have an id attribute will use their text content as the identifier.

    New feature: Regenerate your API key

    We know a lot of you are concerned about security and sometimes you want to make sure you have control over your API keys for SpeedCurve. We added the ability for you to regenerate your API key on demand in your Team settings. As an org admin, navigate to Admin-> Teams and select the team you want to edit. From there, you'll see the option 'GENERATE NEW API KEY'. Just click & confirm and you're all set!

    Test agent updates: Chrome 89, Lighthouse 7.3

    Updated test agents are being rolled out to all regions today. They include updates to several pieces of core software, including:

    • Chrome has been updated from version 88 to 89
    • Lighthouse has been updated from version 7.2.0 to 7.3.0

    Please note that Chrome 89 includes minor changes to Cumulative Layout Shift and First Contentful Paint. These changes may affect the CLS and FCP values on your pages.

    Test agent updates: Chrome 88, Firefox 85, Lighthouse 7.2

    Updated test agents will be rolled on Monday 1 March (NZDT) to all regions. They include updates to several pieces of core software, including:

    • Chrome has been updated from version 84 to 88
    • Firefox has been updated from version 78 to 85
    • Lighthouse has been updated from version 6.1.1 to 7.2.0
    • SpeedCurve now uses Lighthouse's own simulated throttling to more closely match how Lighthouse runs in other environments. This should not have a noticeable impact on your Lighthouse scores.

    There have been several changes in Chrome that may affect your metrics, including some general performance improvements as well as changes to some Web Vitals metrics. While we can't predict how these changes will affect your pages, in general, we have noticed the following trends:

    • Lighthouse performance scores are generally consistent, but are lower for some pages due to LCP and CLS changes mentioned below.
    • CPU scripting time and other CPU-bound metrics like First CPU Idle are slightly lower (JS execution is faster).
    • CPU layout time is lower (layouts are faster).
    • Cumulative Layout Shift (CLS) is slightly higher for some pages. This is more pronounced on mobile.
    • Largest Contentful Paint is higher for some pages.

    Web Performance for Product Managers

    I love conversations about performance, and I'm fortunate enough to have them a lot. The audience varies. A lot of the time it’s a front-end developer or head of engineering, but more and more I’m finding myself in great conversations with product leaders. As great as these discussions can be, I often walk away feeling like there was a better way to streamline the conversation while still conveying my passion for bringing fellow PMs into the world of webperf. I hope this post can serve that purpose and cover a few of the fundamental areas of web performance that I’ve found to be most useful while honing the craft of product management.

    So, whether you are a PM or not, if you're new to performance I've put together a few concepts and guidelines you can refer to in order to ramp up quickly. This post covers:

    • What makes a page slow?
    • How is performance measured?
    • What do the different metrics mean?
    • Understanding percentiles and how to use them
    • How to communicate performance to different stakeholders

    Let's get started...

    Continue reading...

    Joining the SpeedCurve team

    After all the twists and turns of 2020, the unprecedented year ended up with the pleasure of joining the SpeedCurve team and helping to build the tool trusted by so many brands around the world that are striving to improve their customer experience.

    As a developer I've always been fascinated by the web and how it enriches people's lives, and now I am jumping into the very essence of it – how it renders, performs and behaves! Thanks to SpeedCurve for this opportunity, I am so excited to work along with the veterans of the web performance industry (and just plain talented people), as well as to be closer to the performance community.

    Continue reading...

    An Opinionated Guide to Performance Budgets

    Performance budgets are one of those ideas that everyone gets behind conceptually, but then are challenged to put into practice – and for very good reason. Web pages are unbelievably complex, and there are hundreds of different metrics available to track. If you're just getting started with performance budgets – or if you've been using them for a while and want to validate your work – this post is for you.

    What is a performance budget?

    A performance budget is a threshold that you apply to the metrics you care about the most. You can then configure your monitoring tools to send you alerts – or even break the build, if you're testing in your staging environment – when your budgets are violated.

    Understanding the basic premise of performance budgets is pretty easy. The tricky part comes when you try to put them into practice. This is when you run into three important questions:

    1. Which metrics should you focus on?
    2. What should your budget thresholds be? 
    3. How do you stay on top of your budgets?

    Depending on whom you ask, you could get very different answers to these questions. Here are mine.

    Continue reading...