How To Reduce CPU Usage In WordPress: Aim For <50% For Better Server Efficiency

High CPU usage is often caused by plugins that constantly collect data, preload/cache expiration settings in cache plugins, bad bots, no CDN, plugins, and WordPress Heartbeat.

Shared hosting is known for CPU throttling (that’s why it’s so cheap). When your website uses too much CPU, it’s throttled so it doesn’t affect other websites sharing the server. This can lead to a slow website, admin, and even 5xx errors. Before you upgrade, talk to your host and ask if they can spare you some temporary resources while you use this tutorial to optimize your site.

I wrote this guide after getting frustrated with SiteGround’s CPU limits which is a common issue in Facebook Groups. I don’t want to spam you and say “switch hosts” but this was the only thing that fixed it (even after upgrading plans and spending several days optimizing my site). I moved to Cloudways Vultr HF then recently to Rocket.net, but there are plenty of hosts that can reduce CPU usage with Cloudflare Enterprise, more resources, and efficient servers such as LiteSpeed.

Of course I’m an affiliate and want to make money by telling you to switch hosts, but I honestly don’t care who you use. Just think twice before you upgrade plans especially if it’s SiteGround.

 

1. Remove High CPU Plugins

Plugins are infamous for creating background tasks.

Any plugin (or plugin module) that has to collect data will probably be your worst culprit. This can be Wordfence’s live traffic report, Rank Math’s 404 logs and Google Analytics integration, or even plugins like Broken Link Checker and Query Monitor which constantly scan your website.

Some people will tell you to deactivate and reactivate plugins 1 by 1 and make sure they’re lightweight. This is broad advice and can be impractical. You can still use some of these plugins as long as you disable or tweak their settings to use less resources by limiting background tasks. However, some plugins are infamous for increasing CPU usage and should be removed entirely.

Tools You’ll Need:

• Query Monitor – find your slowest plugins. Once installed, view a page on your site, find the Query Monitor menu in your admin bar, and go to Queries → Queries by component.

• WP Hive – free Chrome Extension that lets you browse the WordPress plugin repository and see whether a plugin impacts memory usage (as well as PageSpeed Insights scores).

• WP-Optimize – shows you which plugins (or plugin modules) add the most database overhead. You can also remove tables from old plugins as well as other database junk. This image below shows how using many Rank Math modules can add lots of overhead.

See the full list of 75+ slow plugins.

Plugin	Category	Memory Impact	PageSpeed Impact
Analytify	Analytics	X	✓
Backup Buddy	Backup	X	✓
iThemes Security	Security	X	✓
Broken Link Checker	SEO	X	✓
Jetpack	Security	X	X
Query Monitor	Analytics	X	✓
NextGEN Gallery	Gallery	X	X
Site Kit by Google	Analytics	X	✓
Wordfence	Security	X	✓
wpDiscuz	Comments	X	X
WPML	Translate	X	X
Yoast SEO	SEO	X	✓

 

2. Limit Heartbeat, Autosaves, Post Revisions

These are more background tasks and should be limited.

Heartbeat runs every 15-60 seconds, autosaves are created every 60 seconds while you’re editing, and post revisions are stored every time you update a post (which aren’t limited at all).

Perfmatters does all of these. You can also do it manually with code or many cache plugins let you limit Heartbeat (i.e. FlyingPress + LiteSpeed Cache) as well as the Heartbeat Control plugin.

Limit Heartbeat – creates requests to admin-ajax.php. I would disable it in the frontend and dashboard, then limit post editor to 120s since you probably want it there for autosaves, etc.

Or paste the following code into your functions.php file after the <?php tag.

add_action( 'init', 'stop_heartbeat', 1 );
function stop_heartbeat() {
wp_deregister_script('heartbeat');
}

Increase autosave interval – WordPress stores an autosave every 60s which is a little much. You could increase this to 120s or even to 300s by adding the code to your wp-config.php file.

define('AUTOSAVE_INTERVAL', 300); // seconds

Limit post revisions – WordPress stores a post revision every time you edit a post and hit the publish button. This creates a lot of database bloat since they’re not limited by default. Since you still want a few backups of your old posts (just in case), you could limit post revisions to 10.

define( 'WP_POST_REVISIONS', 10 );

 

3. Limit Preloading In Cache Plugins

Preloading in cache plugins is another culprit. Some plugins let you change how preloading works while other plugins don’t (in that case, try disabling it completely).

• WP Rocket’s preloading
• LiteSpeed Cache’s Crawler
• SG Optimizer’s preheat cache

You should only preload important sitemap URLs. Preloading your entire sitemap means tags and other non-critical pages are preloaded and consumes resources. Find your sitemap URL (i.e. https://example.com/sitemap_index.xml), copy the most important URLs (i.e. pages/posts), and add them manually. Disabling preload entirely is another option since it’s known for increasing CPU usage. The screenshot below is for WP Rocket but the LiteSpeed Cache Crawler and most other cache plugins have options to control how preloading works. Check their documentation.

You can also increase the preload crawl interval using WP Rocket’s helper plugin or again, check your plugin’s documentation. Increasing the default interval from 500ms to 3000ms (or more) prevents your cache plugin from preloading URLs faster than your server can handle.

They have another helper plugin to disable automatic cache clearing. Any time you do one of these things, the entire cache is deleted and rebuilt. A better alternative is to set up a cron job to control when the cache is cleared and which pages are cleared (you can also do this with preloading). This way, you’re not constantly clearing the full cache when updating your website.

Finally, try disabling the “preload links” setting. If users constantly hover over internal links (especially on websites with lots of image links like WooCommerce products), this means those pages are constantly downloading in the background. Similar thing if you’re using Flying Pages.

 

4. Use Cloudflare To Reduce CPU Usage

Cloudflare is your best friend for reducing CPU.

One thing that reduces CPU usage is improving cache hit ratio (with full page caching/APO) since uncached requests to your origin cause more stress than requests cached by Cloudflare.

• CDN: offloads bandwidth to their 270+ data centers.
• Bot fight mode: blocks bad bots from crawling your site.
• Crawler hints: helps search engines avoid wasteful crawls.
• Hotlink protection: stops websites from stealing image bandwidth.
• Browser integrity check: extra layer to block bots/spammers/crawlers.
• Argo: limits number of data centers that ask origin for content (paid service).
• WAF: firewall improves security and reduces usage simultaneously (paid service).
• Firewall rules – block bad bots, hackiest countries, specific URLs, XML-RPC, etc.
• Rate limiting – identifies/mitigates excessive requests to specific URLs (paid service).
• Full page caching: caches HTML to improve cache hit ratio and reduces origin requests.
• Cloudflare Enterprise: Rocket.net has the best Cloudflare Enterprise (compared to Cloudways/Kinsta) mainly because it has full page caching, WAF, and built-in WAF rules to protect your site while only allowing about 10% of traffic to actually hit your origin server.

 

5. Protect Your WP-Login Page

Your login page is a common target for bots/attacks. Even if they don’t successfully login, attempting to create requests. Here’s how to protect the login page and stop these requests.

• Limit login attempts: control how many times users attempt to login, lockout period, XMLRPC gateway protection, and other features using the Limit Login Attempts plugin.
• Move the wp-login page: bots aren’t usually smart enough to find a custom login page which you can change using Perfmatters (if you’re already using it) or WPS Hide Login.
• Use QUIC.cloud to protect the login: if you’re using QUIC.cloud with LiteSpeed, they have several security features to protect the login page, so I wouldn’t move it in this case.
• SiteGround Security plugin: while I’m not a fan of SiteGround, their security plugin can move your login page, limit login attempts, disable XML-RPC, and help protect your site.

 

6. Replace WP-Cron With A Real Cron Job

The wp-cron is loaded on every pageview and schedules automated tasks like publishing scheduled posts, checking for theme and plugin updates, sending email notifications, etc. Replacing this with a real cron job gives you better control and can help reduce CPU usage.

Before setting up an external cron job, the first step is disabling the built-in wp-cron. Add the code to your wp-config.php file before where it says “That’s all, step editing! Happy blogging.”

define('DISABLE_WP_CRON', true);

Now we’ll set up an external cron job. This can be different depending on your host (cpanel, VPS, etc). I suggest Googling instructions for them since SiteGround, Bluehost, Cloudways, and Hostinger all have their own guides. In cPanel, you would open the “cron jobs” tab and use the following line to set a cron job for every 10 minutes. You may think a higher interval would be better for CPU, but this can cause CPU spikes since too many jobs are running at the same time.

wget -q -O - https://yourwebsite.com/wp-cron.php?doing_wp_cron >/dev/null 2>&1

WP Crontrol is nice for changing the schedule of specific cron jobs and deleting jobs with no action. You could also offload cron jobs from your server using a Cloudflare JavaScript worker.

 

7. Install Redis Or Memcached With OPcache

Both help reduce CPU usage, but your host must support them.

 

8. Stop Using Garbage Mainstream Hosts

Avoid mainstream hosts like SiteGround, Hostinger, Kinsta, WPX, Bluehost, and GoDaddy.

Most are shared hosting but lack resources (cores, RAM, or they have strict CPU limits which force you to upgrade). They also use SATA SSDs when NVMe is faster, and Memcached when Redis is faster. Or they have other issues like SiteGround’s Optimizer plugin doing a poor job with web vitals, their DNS getting blocked by Google, history of TTFB issues, and threatening people who write bad reviews (that’s why you don’t see more of them). Hostinger has multiple scam reports and WPX blamed a dead CEO for a global outage. I could go on why you shouldn’t use these, but let’s just say their “marketing” is generally better than their specs. There, I said it.

	SiteGround Cloud Jump Start Plan	WP Engine StartUp Plan	Kinsta Starter Plan	Cloudways Vultr HF (2GB)	Rocket.net Starter Plan (Who I Use)
Type	Cloud	Cloud	Cloud	Cloud	Private cloud
Server	Apache + Nginx	Apache + Nginx	Apache + Nginx	Apache + Nginx	Apache + Nginx
Cores/RAM	4 cores/8GB	Not listed	12 cores/8GB	1 core/2GB	32 cores/128GB
Storage	40GB / SATA	10GB / SATA	10GB / SATA	64GB / NVMe	10GB / NVMe
CDN	Google Cloud	Cloudflare + Polish	Cloudflare + full page caching + firewall rules	Cloudflare Enterprise – APO ($5/mo)	Cloudflare Enterprise
CDN bandwidth	Unmetered	Not listed	100GB	100GB	Unlimited
DNS	Internal (previous issues)	Internal	Amazon Route 53	DNS Made Easy ($5/mo)	Cloudflare
Cache plugin	SG Optimizer	x	x	Breeze	x
Object cache	Memcached	Memcached	Redis ($100/mo)	Redis Pro	Redis
PHP processor	FastCGI	HHVM	FastCGI	FPM	LiteSpeed
PHP workers	Not listed (but common issue)	Not listed (but common issue)	2 PHP workers	No limit	No limit
Memory limit	Adjustable	512MB	256MB	Adjustable	1GB
Database	MySQL	Not listed	Not listed	MariaDB	MariaDB
Nginx reverse proxy	✓	Manual configuration	$50/mo	✓	✓
Bandwidth or monthly visits	5TB	50GB + 25k visits/mo	25k visits/mo	2TB	50GB + 250k visits/mo
Email hosting	✓	x	x	x	x
Malware removal	Scanner only	x	Removal pledge	x	Imunify360
Major incidents	TTFB/DNS/CPU issues, unethical	2015 breach	None	None	None
Migrations	$30/site	Paid (quoted)	Free (most hosts)	1 free + $25/site	Unlimited free
TrustPilot rating	4.6/5	4.5/5	4.2/5	4.5/5	4.9/5
Price	$100/mo	$25/mo when paying yearly	$29/mo when paying yearly	$35/mo with CF Enterprise	$25/mo when paying yearly

Specs of popular cloud hosts

	SiteGround GrowBig	Hostinger Business WP	WPX Business	A2 Hosting Turbo Boost	NameHero Turbo Cloud (Recommended)
Type	Shared	Shared	Shared	Shared	Shared
Server	Apache + Nginx	LiteSpeed	LiteSpeed	LiteSpeed	LiteSpeed
Cache plugin	SG Optimizer	LSC	LSC or W3TC	LSC	LSC
CDN	Google Cloud	QUIC.cloud	QUIC.cloud / XDN	QUIC.cloud	QUIC.cloud
Full page caching	✓	via QUIC	via QUIC	via QUIC	via QUIC
DNS	Blocked by Google for 4 days	Internal / QUIC	Internal / QUIC	Internal / QUIC	Internal / QUIC
Cores/RAM	Hidden	2 cores/1.5GB	1 core/1GB	2 cores/2GB	3 cores/3GB
Storage	20GB / SATA	200GB / SATA	15GB / SATA	Unlimited NVMe	Unlimited NVMe
Object cache	Memcached	Memcached	x	Redis	Redis
Database	MySQL	MariaDB	MariaDB	MariaDB	MariaDB
Resource limits	CPU limits are common	Low resources	Low resources	Efficient with LiteSpeed	Efficient with LiteSpeed
Inodes	400,000	600,000	At discretion	600,000	500,000
Control panel	Site Tools	hPanel	WPX Panel	cPanel	cPanel
Email storage	10GB	1GB	Many limits	Unlimited	Unlimited
Major incidents	TTFB/DNS/CPU issues, unethical	Scam reports, fake reviews, 2019 breach	Global outage blamed on dead CEO	2 week ransomware attack	2 day node outage with apology letter
TrustPilot rating	4.6/5	4.6/5 (fake)	4.9/5	4.4/5	4.6/5
Migration	$30/site	Unlimited	5 free	Unlimited	1 free
Intro price	$3.99/mo (1 year agreement)	$3.99/mo (2 year agreement)	$20.83/mo (1 year agreement)	$6.99/mo (3 year agreement)	$9.98/mo (3 year agreement)
Renewals	$24.99/mo	$14.99/mo	$20.83/mo	$22.99/mo	$19.95/mo
Specs	View	View	View	View	View

Specs of popular shared hosts

Unless you have a fast global TTFB in KeyCDN’s performance test or SpeedVitals, you need to rethink your hosting/CDN setup since those are 2 main TTFB factors. Another solid tool to test hosting performance is the WP Hosting Benchmark plugin. TTFB is also 40% of your LCP score.

Check my GTmetrix report, PageSpeed Insights, click through my site, or read this Facebook thread. You can search Rocket.net’s TrustPilot profile for “TTFB” to see more migration results.

I agree:

 

9. Use PHP 8+

Upgrade to PHP 8.0 in your hosting account (if you see errors, revert to PHP 7.4).

You should also consider increasing:

• Memory limit (at least 768MB)
• Max_execution_time
• Max_input_time

 

10. Disable XML-RPC

If you don’t use mobile devices to publish content (or plugins like JetPack), you should disable XML-RPC not only for CPU reasons, but it also stops brute force + DDoS attacks. To disable it, paste the code in .htaccess and replace xxx.xxx.xxx.xxx with your IP address in case you need it. Alternatively, you can disable XML-RPC in Perfmatters or by using the Disable XML-RPC plugin.

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

 

11. Clean Up Your Admin

Other than making your admin look tidy, disabling things can save resources too.

• Unbloater (recommended)
• Perfmatters
• Disable WooCommerce Bloat
• Hide SEO Bloat (for Yoast)

 

12. Stop Using Elementor/Divi

Elementor made improvements with Experiments and Divi released Performance settings.

However, most of these only affect the frontend while the editors still require a decent amount of server resources especially on shared hosting. I moved from Elementor to GeneratePress but Kadence and Oxygen Builder are good too. If you insist on keeping Elementor or Divi, hard code your header, footer, and sidebar in CSS which is more lightweight than heavy page builder code.

 

13. Disable Unused Hosting Add-Ons

Disabling unused features in your hosting account can also help.

This mainly applies to things like New Relic and xdebug. Just like many diagnostic tools, New Relic has to process a lot of data and should be disabled immediately after you’re done using it.

 

14. Keep Email/Web Hosting Separate

There’s a reason many cloud hosts don’t offer email hosting.

Emails take up indoes (files) and resources which could be better dedicated to hosting your website. Some shared hosts have very low inode limits and even say exceeding them can have an “adverse effect on server performance.” Use a third-party service like Google Workspace (what I use) or Cloudflare who started offering free email addresses. It’s a good idea to keep them separate anyway since in case you switch hosts, you don’t have to switch your email too.

 

15. Block Spam Comments

I recently switched to Antispam Bee (which doesn’t use CAPTCHA) ever since Akismet turned into a paid plugin. Otherwise my blog gets too much spam which isn’t good for CPU or my time.

 

16. Run A Malware Scan

Run a scan using Wordfence or another security plugin to check for malware and other vulnerabilities. Fixing other issues can improve security and may also help reduce CPU usage.

A lot of people have success using Wordfence to reduce CPU, but you’ll probably have to configure quite a few settings or the ongoing scans can actually make your problem worse.

 

FAQs

How do I reduce CPU usage in WordPress?

The easiest way to reduce CPU usage is by limiting preloading in cache plugins, disabling high CPU plugins/modules, and using Cloudflare to offload bandwidth while using bot fight mode, crawler hints, and hotlink protection.

What happens if CPU usage is 100%?

If your CPU usage is 100%, ask your host to spare temporary resources so you have time to optimize your website. You may be able to lower usage so you don't have to upgrade plans.

How do I check CPU usage?

Your hosting dashboard should have tools to check CPU usage as well as memory, bandwidth, and disk space. Or use tools like AWStats, Query Monitor, and New Relic.

I know this can be a pain so feel free to drop a comment if you need help.

Cheers,
Tom