Wordpress Optimization Tips - Reduce High CPU Usage And Load Time

I have a very strong experience of working with very diversified wordpress websites including but not limited to eCommerce websites, directory websites, blogs, corporate website etc.

During all these years working with wordpress, I have faced many issues ranging from high CPU usage on shared hosting to increased page load time. I have read lots of tutorials and experimented with hundreds of wordpress websites to make my websites load blazingly fast with less cpu usage on shared hosting. I am running 10 woocomerce based websites, each with almost 5000+ products on same shared hosting without any issues.

Following are some of my wordpress speed and load optimization tips. Some of them are pretty common and some of them I found while researching for very specific issues.

NOTE - ALWAYS BACKUP FILES OR CODE BEFORE ADDING ANYTHING NEW


1. Plugins
Install only the ones you REALLY REALLY need. I have seen people using multiple plugins for same thing at the same time. Plugins are the major reason that causes CPU load.

Delete all the disabled plugins.

Avoid following plugins and use their alternatives.

ALL IN ONE SEO plugin - very high cpu consumption - Use Platinum SEO Pack instead
Any wordpress STATS plugin - Use google Analytics
NextGen Gallery or Any Gallery Plugin
Disqus Comments = Use builtin comment system (or if you must use it then Disable automated comment importing )
Any Related Posts Plugins (use Jetpack related posts instead)
Broken Link Checker
Really Simple CAPTCHA
Any Post View Counting Plugins
MyReviewPlugin
Sweet Captcha
EWWW Image Optimizer
WP DB manager - Use WP-Optimize instead

Use Plugins
W3 Total Cache = very powerful but can also mess your website. Use wisely or Use Wp Rocket Instead

Wp-Optimize = very useful in optimizing and removing junk form your database.

If you are using Pretty Link - Clear hits olden than 30 days.


2. Update
Update plugins, themes and wordpress whenever a new update is available. It do helps with cpu usage.

3. Themes
Use a theme that is light on resources. Now a days almost every second theme is using Visual Composer. Try to avoid it. Select themes which uses wordpress built in customizer or widgets as page builder.

Delete Unused Themes

4. Woocommerce

Go to Woocommerce > Settings > Default Customer Location - Select No Location By Default

Go to Woocommerce > Settings > Products > Product Ratings > Uncheck Show "verified owner" label for customer review ( disable ratings on review option for better performance)

Every other week, go to Woocommerce > System Status > Tools > and clear WC Transients, Expired Transients and Customer Sessions


5. WP-CONFIG Optimizaition

a. Disable WP-Cron (use manaul cron instead)

define('DISABLE_WP_CRON', true);

b. define website instead of letting wordpress look for it

define('WP_HOME', 'https://www.yourwbesite.com');
define('WP_SITEURL', 'https://www.yourwbesite.com');


c. Increase memory

define('WP_MEMORY_LIMIT', '64M');

d. Restrict Posts Revisions

define (‘WP_POST_REVISIONS’, 3); // limit number of revisions to 3

e. Post Revision Save Time
define (‘AUTOSAVE_INTERVAL’, 160); // in seconds



6. Disable Avatar in Settings > Discussion

7. Check ERROR LOGS on weekly basis atleast. it will help you a lot about load issues

8. Images

a. Go to Settings > Media and make every size 0.

b. Use image compressors like http://compressor.io/ to compress image before uploading

9. Update to PHP 5.6

10. Add Cloudflare.com - Its FREE

11. HTACCESS

Although cache plugins take care of this stuff, but still make sure that you have following enabled in your htaccess

Gzip Compress
Stay Alive
Browser Caching
Expiry Header

12. Theme Functions.php

Add following lines to your theme functions.php

remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
remove_action('wp_head', 'rsd_link');
remove_action('wp_head', 'wlwmanifest_link');
remove_action('wp_head', 'wp_generator');
remove_action('wp_head', 'start_post_rel_link');
remove_action('wp_head', 'index_rel_link');
remove_action('wp_head', 'adjacent_posts_rel_link');


it removes useless scripts & info from header of your theme including emojis, next, previous links, wordpress version, live writer etc


Extra
1. you *may* use P3 plugin from godaddy to check which plugins are causing the load issues

2. You may also use a subdomain to store and load images for your wordpress website. This gives you a parallel loading benefit like CDN

Interesting, anybody have issues removing stuff from functions.php?

How come this post has no comments? it's a great article indeed

Great summary, Easiest one of all is just as he said. Delete any unused plugins & themes.