As with every other theme the final optimization needs to be achieved with a cache plugin.
We highly recommend installing: wordpress.org/support/plugin/swift-performance-lite/
During the activation you can import a config file. Use this one, it’s optimized for the theme. You need to unzip the file before importing it.
Note, that you only should do this when you go into production mode. We don’t recommend it during the development phase of the site.
In addition to the mentioned plugin, you can also use: wordpress.org/plugins/webp-express/ This will implement the new WebP with all necessary fallback to your installation. Learn more about this new format here: https://developers.google.com/speed/webp/
However, Website speed is based on many factors.
1.) Internet Connection Speed (most obvious). If your connection is slow, or at least the connection between you and the website host, the website also becomes slow. So the distance between host and visitor is an important factor and does have straight influence on the test itself. In the end, you need to determine where your host is located and where your target audience is located. By default, GTMetrix for example is testing from Canada. So if your main audience /customers are located in the UK you should consider that when testing. If you have a worldwide audience, you should also consider using a CDN to have a global coverage, which in the end is also more expensive.
2.) Hosting Company and Hosting Package. You won’t believe how different Hosting Plans can perform. Starting from shared hosting to virtual machines etc. If you have an excellent hosting, your website automatically performs much better, and it’s not the higher price you pay, the more speed you get. Example: hetzner.com/de/webhosting We have customers using the 4,78€ Level 4 Package and the speed is beyond amazing, it’s just incredible fast. And then we have people using the hatchling plan of hostgator.com/web-hosting and expect to have a decent speed, but this in the end will not work.
3.) Plugin and themes, of course also a factor. With the most recent version we already changed a lot of in terms of loading. Including lazy load for images and scripts as well as internal CSS caching. But in the end Brooklyn is still a multipurpose theme and not a mobile first solution. We have all these effects / transitions etc. which people like but at the same time these elements also cause additional loading time. Did you know, that for example the website preloader which is a nice user experience does have influence on the test results negatively? It’s not because of the fact, that it does preload images in the background, it is the layout shift and the end. Same with every used animation.