GTmetrix is a website performance analytics tool that you can use to check your website's speed and performance, as well as get useful information on the issues that may affect your website's loading speed and how to improve it.
Step 1 - Preparations
It is recommended to create a GTmetrix account, as it enables the option to choose the test location and device, as well as a few additional options.
Choosing a location closest to your actual server location will provide you with more accurate data than the default location.
Step 2 - Run a Test
Once logged in to GTmetrix, enter your domain name with HTTPS. Next, select the testing server location, device type, and connection speed.
When all is good to go, click on Analyze:
Step 3 - Read the Report
The report contains several sections, it is recommended to check them all:
The following guides cover them in detail: