First we should do to optimize our website is to make a test using such services as Lighthouse or GTMetrix.

Services

1. Lighthouse

Lighthouse is an open-source, automated tool for improving the quality of web pages.

There are several options how we can use it:

• Chrome: Lighthouse is integrated directly into the Chrome DevTools, under the “Lighthouse” panel.
• Using the Chrome extension. The Chrome extension was available prior to Lighthouse being available in Chrome Developer Tools, and offers similar functionality.
• From the command line. You can automate your Lighthouse runs via shell scripts.
• As a Node module. You can integrate Lighthouse into your continuous integration systems.
• Web UI: PageSpeed Insights.

2. GTMetrix

Homepage: GTMetrix.

Optimization steps

Minimize main thread work

Details.

Images optimization

Convert all you images to WebP format. Here’s a good service for this task.