Site Speed
Do you want to speed up your WordPress site? Fast loading pages improve user experience, increase your page views. In this article, we will share the most useful WordPress speed optimization tips to boost WordPress performance and speed up your website.
This is what we have done on our demo site to improve the loading time. You could try to follow it to improve your website's speed.

Choose a good host

When starting out, a shared host might seem like a bargain if you don't have too many visitors. We are using the hosting of Siteground for our demo site. But if you have more than 1000 visitors per day, you should use a VPS, or at least a higher plan of shared hosting.
Recommend: WPEngine or SiteGround

Install a WordPress Caching Plugin

WordPress plugins are obviously quite useful, but some of the best falls under the caching category, as they drastically improve page loads time, and best of all, all of them on WordPress.org are free and easy to use.
We are using WP Super Cache for our demo site. Besides this plugin, W3 Total Cache is also another good choice.

Combining CSS, JS, and HTML

Using Autoptimize for combining CSS, JS, and HTML. Even the cache plugin supports combining those files, but sometimes it breaks JS scripts. Therefore we usually use this plugin for better combining and minifying files.

Use a content delivery network (CDN)

Remember how we mentioned above that users in different geographical locations may experience different loading times on your site? That’s because the location of your web hosting servers can have an impact on your site speed.
For example, let’s say your web hosting company has its servers in the United States. A visitor who’s also in the United States will generally see faster loading times than a visitor in India.
Using a Content Delivery Network (CDN) can help to speed up loading times for all of your visitors. A CDN is a network made up of servers all around the world. Each server will store “static” files used to make up your website.
These static files include unchanging files such as images, CSS, and JavaScript, unlike your WordPress pages which are “dynamic” as explained above. When you use a CDN, every time a user visits your website they are served those static files from whichever server is closest to them. Your own web hosting server will also be faster since the CDN is doing a lot of the work.
We use recommend using Cloudflare or Bunny CDN...
It works well with WordPress websites and compliments your existing WordPress caching plugins for even faster loading times.

Optimize images

Images bring life to your content and help boost engagement. Researchers have found that using colored visuals makes people 80% more likely to read your content.
However, if your images aren’t optimized, then they could be hurting more than helping. In fact, non-optimized images are one of the most common speed issues that we see on beginner websites.
Before you upload a photo directly from your phone or camera, we recommend that you use photo editing software to optimize your images for the web.
In their original formats, these photos can have huge file sizes. But based on the image file format and the compression you choose in your editing software, you can decrease your image size by up to 5x.
At WPBeginner, we only use two image formats: JPEG and PNG.
Now you might be wondering: what’s the difference?
Well, PNG image format is uncompressed. When you compress an image it loses some information, so an uncompressed image will be higher quality with more detail. The downside is that it’s a larger file size, so it takes longer to load.
JPEG, on the other hand, is a compressed file format which slightly reduces image quality, but it’s significantly smaller in size.
So how do we decide which image format to choose?
If our photo or image has a lot of different colors, then we use JPEG. If it’s a simpler image or we need a transparent image, then we use PNG. The majority of our images are JPEGs.
Below is a comparison chart of the file sizes and different compression tool that we could have used for the StrangeLoop image used above.
Image speed chart As you can see in the chart, the image format you use can make a HUGE difference in website performance.
Yahoo! has an image optimizer called SmushIt that will drastically reduce the file size of an image, while not reducing quality. However, if you are like me, doing this to every image would be beyond a pain, and incredibly time-consuming. Fortunately, there is an amazing, free plugin called WP-SmushIt which will do this process to all of your images automatically, as you are uploading them. No reason not to install this one.

Reference article

15 Easy Ways to Speed Up WordPress
Sparring Mind
24 Tips to Speed Up WordPress Performance (UPDATED)
WPBeginner
The Ultimate Mega Guide to Speeding Up WordPress
WPMU DEV Blog
How to Speed Up WordPress Performance
WebsiteSetup
18 Tips on How to Speed up WordPress - KeyCDN
KeyCDN
Last modified 3mo ago