Page Speed Benchmarks is an interactive dashboard that lets you explore and compare web performance data for leading websites across several industries – from retail to media – over the past year. This dashboard is publicly available (meaning you don't need a SpeedCurve account to explore it) and is a treasure trove of meaningful data that you can use for your own research.
The dashboard allows you to easily filter by region, industry, mobile/desktop, fast/slow, and key web performance metrics, including Google's Core Web Vitals. (Scroll down to the bottom of this post for more testing details.)
At the time of writing this post, these were the home pages with the fastest Start Render times in key industries:
As you can see, I've included Largest Contentful Paint alongside Start Render in this chart, for reasons I explain below.
Numbers are good, but visuals are even better. Below you can see the fastest sites – ranked by Start Render time – in each category, along with screenshots taken from their rendering timelines, which show you what the viewer sees at key render moments:
These visuals are a great tool for validating the best metrics to focus on for your pages. Looking at the screenshots below, you can really see the disparities between metrics, especially for pages served to mobile.
The Guardian (view desktop test results)
El Pais (view mobile test results)
LA Times (view desktop test results)
LA Times (view mobile test results)
Jiji (view desktop test results)
Nikkei (view mobile test results)
Carrefour (view desktop test results)
Edeka (view mobile test results)
Amazon (view desktop test results)
Wish (view mobile test results)
Rakuten (view desktop test results)
Yodobashi (view mobile test results)
Airbnb (view desktop test results)
Skyscanner (view mobile test results)
HomeAway (view desktop test results)
Lonely Planet (view mobile test results)
Rakuten Travel (view desktop test results)
Expedia (view mobile test results)
Visual feedback that something is happening on the page is important to users. This is why it's frequently proven to be a good metric to use when creating correlation charts that map performance to user engagement and business metrics, like bounce rate and conversion rate.
To me, the biggest takeaway here is noting the disparity between Start Render and Largest Contentful Paint. Some disparity is to be expected, as Start Render measures when the first pixels start to appear on the page, and LCP measures when the largest visual element (image or video) finishes rendering.
In most cases, the difference between Start Render and Largest Contentful Paint isn't huge for pages served to desktop. Mobile tells a different story, even among the fastest pages we tested. For example:
While those were the most glaring examples, most of the other sites also had significant differences. There's also this gotcha...
If you're serving a lot of mobile users, you may want to validate that LCP is a valid metric to track – and troubleshoot any issues that are preventing it from being measured correctly.
Visually Complete was a helpful metric for its time, but it came with its fair share of gotchas – such as the fact that it sometimes didn't fire until long after the page had fully rendered. You can see examples of this above. While we still track Visually Complete in SpeedCurve for folks who are still using it, we consider it unofficially deprecated in favour of more precise metrics.
Here's how we set up testing for the Page Speed Benchmarks:
I also encourage you to check out the entire Industry Page Speed Benchmarks dashboard (no login required). You can drill down into the historical test data for every site. If you spot something interesting, let me know!