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Web performance, SEO, Core Web Vitals & holiday readiness

Nov 1, 2021


Hi there,

Here at SpeedCurve, we don't make a big fuss about holiday readiness. There are a couple of reasons for this:

  • You're probably already flooded with marketing emails about Black Friday. (I know I am!)
  • We think you should care about performance all year round, not just during the holidays.

Having said that, in this newsletter we've corralled some resources that retailers (and others) might find helpful – not just now, but for the entire year. We're also sharing some of the latest updates about Google's page experience ranking signals and some other helpful resources that will help you optimize for SEO and beyond.

Until next time,



Google Search updates

Google recently announced they'll begin using page experience as part of their desktop search ranking system, beginning in February 2022.

Page experience ranking signals include:

  • Largest Contentful Paint (LCP)
  • Cumulative Layout Shift (CLS)
  • First Input Delay (FID)
  • HTTPS Security
  • Absence of intrusive interstitials
  • Mobile friendliness

Measuring and optimizing for SEO

In light of Google's announcement, I wrote this blog post, which covers FAQs I routinely hear from SpeedCurve users:

  • How much does web performance matter when it comes to SEO?
  • Which performance metrics should you focus on for SEO?
  • What can you do to make your pages faster for SEO purposes?
  • What are some of the common issues that can hurt your Web Vitals?
  • How can you track performance for SEO?

Web performance for retailers

Is your site ready for Black Friday (and every other day)? How does your site's speed rank against your competitors? What are the most common performance issues that plague retail sites? How can you identify (and fix) them? Get the answers here.

Want to make your site faster? Consulting can help.

Our aim is to make it easy for you to track the performance of your site, when it changes, and what caused the change. But we've generally left it up to you to use our tools to identify areas where performance needs to improve and what optimizations would make it faster.

Now that Andy (@AndyDavies) has joined our team, we offer consultancy services to help fill those gaps. Whether you're interested in a one-off performance audit, help and advice on an ongoing basis, or something else performance related, feel free to start the conversation by sending us a note at

New and improved 'light' theme

Did you know that SpeedCurve has a light theme? We do! And we recently made some improvements to make it even more visually pleasing and user-friendly. To check it out, log in, click the ellipse at the top-right corner of any dashboard, and toggle from dark to light.

Test agent updates: Chrome 95, Firefox 93, Lighthouse 8.6

We've released the latest version of our synthetic test agents to all regions. This release includes updates to several pieces of core software, including:

  • Chrome has been updated from version 91 to 95
  • Firefox has been updated from version 85 to 93
  • Lighthouse has been updated from version 8.0.0 to 8.6.0

ICYMI: RUM Sessions dashboard is live!

Want to understand how people actually experience your site? Then you need to monitor real users. With your Sessions dashboard, you can drill down and segment your RUM data by:

  • Metric / duration
  • Browser
  • Location
  • Time period

Web Performance 101: What is performance and why does it matter?

I was so excited to speak again at this year's Chrome Dev Summit. (You can find my slides here.) My workshop covered:

  • Why should you care about performance?
  • How can you measure it?
  • How do you get other people in your organization to care?
  • An overview of the history of performance metrics, up to and including Core Web Vitals.

From the #webperf community...

  • Rachel Andrews rounded up everything you need to know that came out of this year's Chrome Dev Summit.
  • On the Shopify blog, Oliver Lindberg offers 12 tips to get your site ready for Black Friday and the holiday season.
  • Jason Merriman shares the five pillars of performance engineering – from content delivery to performance evangelism – at This is a great piece about how an organization with a lot of performance maturity got to this point.
  • Simon Hearne always has great optimization how-tos, and his latest post about creating fast and responsive hero videos is a fantastic resource.
  • Edgar Sanchez wrote an insightful, detailed three-part series documenting how BuzzFeed tackled their issues with Cumulative Layout Shift as part of their broader Core Web Vitals initiative. Start with part 1 here.