How device capabilities might impact your site speed

Summary: That smartphones come in many types and price ranges we all know. But do you also know that this can have a lot of impact on your site speed and the user's experience?

How device capabilities might impact your site speed

The difference in device capabilities

When you buy a smartphone you are usually looking for something in a certain price range. This may be because this is your budget or simply preferred. But what different classes of smartphones are there, and what is the difference?

Low-end devices

Typically, anything in the $50 - $199 range is considered a low-end device. Smartphones in this class often have between 2GB and 4GB of device memory. Besides that, they often have a cheaper CPU, which causes these phones to process some tasks less well.

In the US, we're still seeing over a quarter of Android devices with 2GB RAM or less. That's a lot of low-end devices.

Annie Sullivan

Mid-range devices

For between $199 and $399 you could get yourself a mid-range device. These often have 4GB or 6GB of device memory. This combined with a good CPU allows certain tasks to be processed faster than a low-end device, thus increasing the user experience.

High-end devices

Anything over $399 is considered a high-end device. These often have 8GB of device memory. However, the iPhone 13 and 14 only have 6GB of device memory, but the tight integration between iPhone hardware and iOS makes up for that difference.

High-end devices are good at handling a lot of tasks at the same time, which makes it easier to get away with using JavaScript.

What devices are my visitors using?

Good question. The best way to find out is to use real user monitoring. With our tooling, we can see exactly how much impact device memory has on certain metrics, such as FCP, LCP, FID, and the new INP.

In case you don't have access to insights from real user monitoring, you can make a rough estimate based on where your visitors are coming from. In the data below you can see what percentage of the annual salary it takes to afford an iPhone 14.


Is your audience typically within one of the countries at the right? Good for your business. You might not have any performance challenges.

But is it typically from a country on the left? You might then have a harder time optimizing UX metrics, such as FCP, LCP, FID, and the INP.

Why device capabilities matter for site speed

Many websites are full of JavaScript. This is the biggest bottleneck when it comes to low-end devices.

Javascript requires a lot of processing. With more device memory, this goes faster because multiple tasks can be performed simultaneously.

On the screenshot, you can see that each step toward more device memory also boosts the site speed for the user. And that users with a low-end device are more likely to fall into the red bucket (poor user experience).

Today, it is not just about internet speed. Your webshop's performance and its conversion also is about device conditions.

Conclusion: What does this mean for developers?

The first thing you need to know is where your actual visitors are coming from and what devices they are using. Real user insights allow you to weigh what is necessary on your website and think about the amount of JavaScript and plug-ins you decide to use.

Want to get important insights into what type of device your users have, what Internet connection they use, and a lot more? Contact us to discuss the possibilities or simply create an account.

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