There are 3 metrics to pay attention when measuring your website’s performance are the Core Web Vitals:
Largest Contentful Paint (LCP): how long it takes for the largest image & text to load on the site. This is the most common way of measuring how long it takes for a site to be fully loaded for a visitor.
Interaction to Next Paint (INP): how quickly a web page responds to any action performs on the website (i.e. clicking a button or typing).
Cumulative Layout Shift (CLS): this is a measure of how “stable” the website is when loading (i.e. do images load in and stay in place or do they shift up/down when loading in the website)
Together, these 3 Core Web Vitals measure the speed, interactivity, and stability of your website. The play a critical role in Google’s ranking algorithm and have strong relationship with your website’s conversion rate and overall customer experience.
In short, websites with better Core Web Vitals have better search rankings, better conversion rates, and an provide a better user experience.
Here are the benchmark to aim for with LCP, INP, and CLS:
LCP — 2.5 seconds or less
INP — 200 milliseconds or less
CLS — 0.1 or less
Here is the LCP, INP, and CLS for Noshinku:
LCP
Mobile: 2.4 seconds
Desktop: 2.4 seconds
INP
Mobile: 103 ms
Desktop: 45 ms
CLS
Mobile: 0.05
Desktop: 0.03
Overall, the Noshinku site has solid performance on mobile and desktop devices 👍
The site’s loading time, interactivity, and stability are not issues that are hurting it’s performance
That said, any improvements in the site’s loading time would be very accretive for the company (i.e. increase conversion rates, improve SEO, decrease CAC, improve overall customer acquisition cost)
Small improvements in your site’s performance can drastically improve conversion rates
1 second improvement in page load time will increase mobile CVR by up to 27% (
This is why major ecommerce brands will spend tens-to-hundreds of thousands of dollars on their website’s performance.
Personally, I’ve seen ecommerce websites improve their conversion rates by 50%+ by making their website load faster.
According to the audit results, the #1 issue slowing down the website: Excess/Unused JavaScript and CSS code
This is a the most common occurrence in ecommerce sites hosted on Shopify. Every app installed, theme change, and third party script (i.e. Facebook Pixel, Google Analytics, etc.) injects code into the site.
Even if the app/theme is removed, the code stays behind, accumulating over time.
Look at the Diagnostics section from the site speed audit below. Notice the 4 instances where JavaScript and CSS code are slowing down the website? Based on how Shopify apps work, this is the most common issue slowing down websites hosted on the platform.
A full codebase optimization would improve the site’s performance further
During this process, necessary JavaScript and CSS code is compressed to run more efficiently.
Unused JavaScript and CSS code is deleted altogether.
This would also improve “main thread” operations — another technical issue slowing down the website. The “main thread” is the order in which the browser loads the website. Streamlining the codebase helps the browser load it faster.
As I said before, the site’s performance isn’t hurtingthe business; however, improving it further is something to keep top of mind as it would be accretive to the business as a whole:
to help ecommerce companies maximize their conversion rate through proper site speed optimization. To date, we’ve helped more than a dozen Shopify sites increase their CVR by 20-50% through site speed optimization.
If you’re every curious about Shopify site performance or the work we do at Roadrunner: