Improving website speed is an ongoing process that requires regular monitoring and optimization.
By following these tips and testing your website regularly, you can ensure that your website is fast, reliable, and provides a great user experience.
Here we review steps developers can take in order to make a website faster

• Test website performance:

Website speed tests assess how a website is performing. Testing a website regularly can help developers track performance downgrades or improvements.
A speed test should also help developers identify some or all of the areas slowing website performance, and where the areas for improvement are. There are plenty of high-quality site speed tests for measuring performance, many of them free. WebPageTest.org (which partners with Cloudflare) has several free tests and produces detailed breakdowns of how quickly individual elements of a page load. WebPageTest.org also allows developers to test websites for different devices and network connection speeds. Google also offers Page Speed Insights for detailed performance testing. Google Chrome DevTools can also help developers in assessing their site's performance; the Network tab shows all HTTP requests, how large the requested assets are, and how long requests take before they're fulfilled.

• Use a CDN (content delivery network):

CDNs boost the speed of websites by caching content in multiple locations around the world.
CDN caching servers are typically located closer to end users than the host, or origin server. Requests for content go to a CDN server instead of all the way to the hosting server, which may be thousands of miles and across multiple autonomous networks from the user. Using a CDN can result in a massive decrease in page load times.

• Optimize images:

Images comprise a large percentage of Internet traffic, and they often take the longest to load on a website, since image files tend to be larger than HTML and CSS files.
Luckily, image load time can be reduced via image optimization. Optimizing images typically involves reducing the resolution, compressing the files, and reducing their dimensions, and many image optimizers and image compressors are available for free online.

• Minify CSS and JavaScript files:

Minifying code means removing anything that a computer doesn't need in order to understand and carry out the code, including code comments, whitespace, and unnecessary semicolons.
This makes CSS and JavaScript files slightly smaller so that they load faster in the browser and take up less bandwidth. On its own, minification will result in only minimal speed improvements. However, implemented along with these other tips, it will result in better website performance.

• Reduce the number of HTTP requests if possible:

Most webpages will require browsers to make multiple HTTP requests for various assets on the page, including images, scripts, and CSS files. In fact, many webpages will require dozens of these requests.
Each request results in a round trip to and from the server hosting the resource, which can add to the overall load time for a webpage.
Additionally, with resources loaded from several different providers, a problem with one of the hosts could impact the webpage's ability to load quickly, or at all. Because of these potential issues, the total number of assets each page needs to load should be kept to a minimum. Also, a speed test should help identify which HTTP requests are taking the most time. For instance, if images are causing a page to load slowly, developers can look for a faster image hosting solution (such as a CDN).

• Use browser HTTP caching:

The browser cache is a temporary storage location where browsers save copies of static files so that they can load recently visited webpages much more quickly, instead of needing to request the same content over and over.
Developers can instruct browsers to cache elements by adding headers to the server's HTTP responses. This can result in significant speed improvements, as the browser can serve cached files without making additional requests to the server.

• Use lazy loading:

Lazy loading is a technique where the loading of certain elements on a webpage, such as images or videos, is deferred until the user scrolls down to that section of the page.
This can greatly improve the initial loading time of a webpage, as it reduces the number of elements that need to be loaded at the start.

• Use a Content Management System:

Content management systems such as WordPress, Joomla and Drupal are built to be highly customizable and extendable, but they also add a lot of unnecessary weight to your website.
This can slow down your site, and make it harder to optimize. If you're looking to optimize your website's speed, you might want to consider using a lightweight Content Management System that is designed specifically for speed and performance.

• Optimize your code:

Optimizing your code can help speed up your website by reducing the amount of time it takes for the browser to process the code and render the page. Some ways to optimize your code include using a code compressor and minifies, using a code profiler to identify bottlenecks and slow areas, and using a code optimizer to improve the efficiency of your code.

• Keep your website up to date:

Keeping your website up to date is important for both security and performance. Make sure that you are using the latest version of your Content Management System and any plugins you have installed. Additionally, keep your server software up to date, including your web server, PHP and database software.

Author NOTE: Those tips are here to give you an idea about "HOW TO" improve website speed. You don't need to follow them if you don't want.