WordPress has become the most famous overloading high CPU script in the world. This is mainly thanks to it's popularity with new users. The good news is, even as a new user, optimizing WordPress is pretty easy if you take some time and follow the steps below.

We listed each optimization for WordPress in order of most helpful.

Before starting, we suggest making a full back up of your WordPress website and database.

1. Update everything
   Old plugins, WordPress versions, or outdated themes, are the main reason for overloading and hacking issues. You should be updating everything in your WordPress at least once a month and a good Theme should be updated at least every 6 months.
   
2. Update your PHP version in your cPanel
   You may have newer PHP versions available. You can check for this in your cPanel in the multiPHP section. Always start with the newest PHP version, and only change to older versions if you have to. PHP version changes take about a minute to update, you will need to click refresh on your browser page to see that the changes are working o.k.
3. Install the JetPack plugin
   Without any caching in your WordPress it has to check every link, image, tag, and more to load each page. To avoid running everything for each visit, there is JetPack. JetPack also has many other important WordPress optimizing features. You can choose the free version, but you do need to choose a package and link it with your WordPress account. We suggest turning on:
   
   Brute force attack protection
   Allow users to log in to this site using WordPress.com accounts
   Speed up image load times
   Speed up static file load times
   Enable site accelerator
   Enable Lazy Loading for images
   Display images in a full-screen carousel gallery
   Use the LaTeX markup language to write mathematical equations and formulas
   Compose using shortcodes to embed media from popular sites
   Add sharing buttons to your posts and pages
   Let visitors use a WordPress.com, Twitter, Facebook, or Google account to comment
   Enable comment likes
   Let visitors subscribe to new posts and comments via email
   Enable the “subscribe to site” option on your comment form
   Enable the “subscribe to comments” option on your comment form
   Generate shortened URLs for simpler sharing.
   Generate XML sitemaps
   Verify site ownership with third party services (At least verify with Google here)
4. Add the Akismet plugin
   This will block spam and junk from wasting your sites resources. It's a must of have for any site overloading. Don't worry, there is a free version for this. Just scroll to zero when it asks for how much you want to pay. You will need to get a free key and register it.
5. Make smaller pages and add Lazy Load
   Making your pages smaller will have a major impact on your load. In fact splitting your page in half will normally lower more than half your load use. If you are still dead set on a long page than at least add a lazy Load plug in like Jetpack. The common amount of posts on a page is 5, anything over that is at risk of having load issues.
6. Remove tags
   Tags seem like a great way to tell Google what SEO traffic to send to your site. The truth is Google has said many times it does not use tags for SEO purposes. Being the third most common reason for overloading WordPress and with no real SEO benefit removing tags is a great way to lower your CPU and load use. We suggest that when you remove tags, to make sure and use sufficient categories to help your visitors navigate well.
7. Remove unneeded plugins
   Every plugin adds more work for WordPress to process with every visit. Removing any plugins not needed, can help your WordPress site run faster and safer. It's a good rule of thumb to stay under lucky 7.
8. Remove admin-ajax
   It's too detailed to explain how to disable admin-ajax in this list, but we have put together a nice blog post showing how you can here: Remove Admin-Ajax
9. Remove wp-cron
   It's also too detailed to explain how to disable wp-cron in this list, but we have put together a nice blog post showing how you can here: Disable wp-cron.php
10. Limit login attempts
    It is important to block hackers and attackers, there is multiple plugins for this including Jetpack.
11. Keep media compressed well
    Having large images and media requires more time to load which adds more load use.
12. Disable WordPress XML-RPC with .htaccess
    

    You can disable all xmlrpc.php requests from the .htaccess file before the request is even passed onto WordPress.

    Simply paste the following code in your .htaccess file:

    # Block WordPress xmlrpc.php requests
    <Files xmlrpc.php>
    order deny,allow
    deny from all
    allow from 123.123.123.123
    </Files>

    
    
    

There is many other ways to help WordPress, these are just the top ones that really should be done to any new WordPress that plans on getting a substantial amount of traffic.