This test will check whether your website (and ultimately the server your website is hosted on) has gzip or brotli enabled by connecting to your domain and requesting the necessary information. Next to that it will also give you some additional information, like the file size of the original version of the web page you test and how much you (may) benefit from using gzip compression.
Since a compressed file is much smaller in file size (bytes) compared to the original web file, the website will need less time to fully load.
Go here for a detailed guide explaining how to enable gzip and for more information about gzip in general.
Brotli is a new open source data compression method. In the majority of cases Brotli can compress files to a smaller size than gzip can, it is therefore generally a better compression method compared to gzip.
Test and analyze the loading times of your website.
Minimize CSS scripts and files for page speed.
Check how and whether your website files are cached.
Check whether your web pages have Gzip compression enabled.
Minify your JS files and scripts to maximize performance.
Tests your image delivery so you can improve it.
Reduce your PNG image filesize while keeping quality.
Play with the quality and size of JPEGs to save disk space.
Place multiple images in one image to make fewer requests.
Analyze your CSS to make improvements to the CSS Delivery.
Test your web pages for broken links and requests.
How many HTTP requests do your web pages produce?
Encode JPEG and other files into a Base64 string.
Check whether your website has keep-alive settings as enabled.
Check the HTTP server header of your site.