A guide on how to test with mobile devices using GTmetrix.
Overview
GTmetrix PRO users have access to mobile testing, both, through a real hardware solution (Chrome Android, Galaxy Nexus, Vancouver only), and our Simulated Devices testing, which enables you to test and monitor your page with more than 40 different devices and variants.
We’ve previously talked about why you should test your webpage’s mobile performance in another article.
In this guide, we’ll explain the differences between the two GTmetrix mobile testing solutions and show you how to perform mobile tests with them.
GTmetrix mobile test offerings
GTmetrix offers two types of mobile device testing, namely:
- A real-hardware Android device located in our Vancouver, Canada location.
- Simulated Device testing in all locations available in your plan tier*.
* Premium Test Locations are not available to Legacy PRO users. Learn more.
Learn more about the differences between these solutions below.
Real-hardware Tests
Our real-hardware device – Chrome (Android, Galaxy Nexus) is an actual Android mobile phone located in our Vancouver, Canada data centre that allows you to generate reports based off actual page loads on this device.
This device would be equivalent to a lower-end Android device, with lower CPU and memory specifications.
To ensure capacity and hardware maintenance ability, we limited usage to manual tests on our webtool in our Vancouver, Canada location.
Note that more capacity is planned for the future as usage increases, as well as, more device options (like iPhones or other Android devices) as we mature the service.
Additional caveats for our Android, Galaxy Nexus mobile device:
- Legacy Reports only (PageSpeed/YSlow metrics)
We’re working on bringing Lighthouse testing soon.
- Older Chrome version
This is due to software limitations, which may cause issues with certain SSL certficates.
- Limited Analysis Options
Only “Cookies” and “Stop test onload” are available due to software limitations.
Simulated Device Tests
Our Simulated Device testing option works by passing parameters to the GTmetrix browser to present itself as a specific device when it requests your website.
When your server receives this request, it treats GTmetrix as the device specified and delivers assets, layouts, etc intended for it.
Three parameters are changed in order for GTmetrix to simulate a device:
- Screen Resolution
- User Agent
- Device Pixel Ratio
With Simulated Device testing, you can generate Lighthouse reports, giving you access to Web Vitals data, along with other important performance insights. Moreover, monitoring and API are also available, in all locations available in your plan tier*.
* Legacy PRO users don’t have access to Premium Test Locations. Learn more.
It’s important to note that Simulated Devices do not simulate hardware performance, and thus actual loading behaviour may differ on a real device.
Learn more about Simulated Device testing here.
How to perform mobile tests with GTmetrix
Ensure that you’re logged in to your GTmetrix PRO account so that you can run a mobile test.
Testing with Real-hardware Android
Follow the instructions below to generate a mobile test report with our Chrome (Android, Galaxy Nexus) device:
1) On the Dashboard, input your URL, and click on Analysis Options
2) Select Chrome (Android, Galaxy Nexus) in the “using” dropdown
This option is available in the Test Format section.
Due to hardware limitations, you are limited to the Analysis Options you can set on your tests. In addition, our Chrome Android device is only available in Vancouver, Canada and provides Legacy Reports only.
3) Click Analyze
GTmetrix should now load your page on our Android device and display a report.
Testing with Simulated Devices
Follow the instructions below to launch a Simulated Device Test:
1) On the Dashboard, input your URL, and click on Analysis Options
2) Select the device you wish to simulate in the “using” dropdown
This option is available in the Test Format section.
3) Select an appropriate Location and Connection Speed for the test
These options are available in the Test format section.
It’s recommended when testing with Simulated Devices to change the connection speed to one that a mobile device would be using. More on why this is important.
Also, be sure to test from the location of where your mobile visitors are likely to visit your page from.
4) Click Analyze
GTmetrix should now load your page using the chosen mobile device’s parameters and display a Simulated Device report.
Throttle your Simulated Device tests to mobile speeds
Mobile phone users in different parts of the world may experience a wide range of Connection speeds from Wi-Fi to mobile data connections (LTE/3G/2G) to access online content.
In order to truly get a realistic picture of your mobile webpage’s performance, it’s recommended to throttle the Connection Speed in line with what your mobile visitors would be using.
GTmetrix provides the following mobile connection speeds to test with (Download/Upload speeds, latency in brackets):
- LTE Mobile (15/10 Mbps, 100 ms)
- 3G Mobile (1.6 Mbps/768 Kbps, 200 ms)
- 2G Mobile (240/200 Kbps, 400 ms)
Alternatively, you can also add your own Custom Connection Speed. Learn more here.
When throttled, you will be able to see the effects of the Connection Speed in the timings of various page metrics and in the Waterfall Chart.
By understanding what your slowest users are seeing, you can set up your page to deliver a great user experience to the majority of your visitors.
Why are my GTmetrix mobile scores different from PageSpeed Insights/web.dev?
There are considerable differences in the mobile testing solutions offered by GTmetrix and the Google tools (PageSpeed Insights/web.dev).
Our real-hardware solution (Chrome Android, Galaxy Nexus) can only generate Legacy Reports while the Google tools are powered by Lighthouse.
Our Simulated Device tests, however, are powered by Lighthouse; yet, there are several implementation differences, which can yield different results.
We’ve written a comprehensive blog article covering these individual differences between GTmetrix and PageSpeed Insights/web.dev.
Summary
Follow the instructions outlined in this article to perform mobile device testing for your webpage, and use those insights to ensure that you’re providing a good user experience to all users, regardless of device used to access your content.
Test with mobile devices on a GTmetrix PRO plan
Mobile testing is available on all PRO plans, along with more test locations, Advanced Analysis Options and more.
You’ll also get Priority access for tests, More Monitored Slots, Hourly Monitoring (select plans only), Remote Location Monitoring (including Premium Test Locations), and more.
