How to Fix High CPU Usage Issue in WordPress Site

#wordpress #webdev #devops #performanceoptimization

In day-to-day software engineering, WordPress high CPU usage is a common issue we often encounter on servers hosting WordPress sites. We usually have no clear clue or reason why the CPU consumption is so high. There are multiple possible causes behind this, and in this blog, we’ll discuss what triggers high CPU usage and how to identify and fix it with nine effective solutions.

What Causes High CPU Usage in WordPress?

When your WordPress website is causing too much strain or load on the server, it’s usually not built efficiently by plugins or themes.

Assume that you are including a plugin that adds related post to all the pages. If it fetches data from the database every time someone views a page, and there’s no caching taking place, that will have a negative impact on performance. Some themes also waste resources, they might be beautiful, but are equipped with too many features or animations that keep running in the background and chew up server power.

WordPress itself can even be heavy in weight. As an example, there is a file named wp-cron.php that carries out things such as update checking or cron-scheduled posts. For high-traffic sites, this file is triggered on each site visit, adding to the load.

More immediately is the issue of traffic both human and robot. Should one of your blog posts unexpectedly gets shared and you receive thousands of visitors, your CPU usage will skyrocket, of course. But not all traffic is good. Bots can bear down on your site by attempting logins, scraping content or looking for vulnerabilities. They send a high number of requests in a short amount of time, which make WordPress continue running scripts and querying the database. And if your site has become infected with malware, it may even be carrying out covert duties in the background for example, sending spam or participating in a botnet without your knowledge.

And it depends a lot on your hosting set-up, too. Shared hosting, specifically, provides you with few CPU and memory. So even a little traffic might be too much. And if your server uses outdated versions of PHP, it will chug along even slower. By updating the version to something newer, like PHP 8 or beyond, you can already make a significant difference.

What is the Ideal Solution

When it comes to tackling high CPU usage on WordPress sites, having the right server management platform makes all the difference. ServerAvatar simplifies this by giving you complete visibility and control over your server’s performance.

What is ServerAvatar?

ServerAvatar is platform to simplify hosting and management of servers and applications. It simplifies process of deploying and managing PHP and Node.js based web applications on servers. If you’re using ServerAvatar to manage your servers and applications, deploying and managing your WordPress is incredibly simple with one-click application installer.

With its real-time monitoring of CPU, RAM, and disk usage, along with built-in tools like caching, firewall, Fail2Ban, automatic SSL, and log management, you can quickly identify and resolve resource-hogging processes.

Unlike traditional hosting panels, ServerAvatar also lets you deploy and manage servers directly from top cloud providers, so you can scale resources effortlessly as your website grows. This makes it an ideal solution for WordPress users who want optimized performance without the headache of manual server management.

Advanced Monitoring Features:

Real-time Performance Graphs – Visual CPU, RAM, and disk usage
Customizable Alerts – Notifications for threshold breaches
Historical Data Analysis – Performance trend identification
Slow Script Detection – Identify resource-heavy processes
Database Query Monitoring – Optimize slow queries

Proactive Notification System: Configure thresholds for CPU usage (e.g., send an alert if CPU is above 80% for 5 minutes). This proactive notification means you often know there’s a problem before your users even notice, allowing you to investigate using detailed performance graphs.

Quick Fixes to Instantly Reduce WordPress CPU Usage

Let’s explore 10 different ways to bring down CPU utilization on servers:

1. Keep WordPress Core, Plugins, and Themes Updated

Once you have done away with any unusable plugins, make sure your WordPress core, all of your plugins, and your theme are updated. Performance improvements and bug fixes (which could lower CPU) are is updated second versions potentially. Older software are often bloated or insecure, causing more resource usage.

Update Priority Order:

WordPress Core – Security patches and performance improvements
Active Theme – Template optimization and bug fixes
Essential Plugins – Security, caching, and SEO plugins first
Remaining Plugins – Update during low-traffic periods

PHP Performance Upgrade: As much as possible, it is advisable to use PHP 7.4+ in WordPress. At the time of this writing, PHP 7.4 is the minimum supported PHP version for WordPress, PHP 8.0 and 8.1 are “compatible with noted issues”, and PHP 8.2 is under “beta support”.

His server stack is properly configured and optimized for speed and security and will run your updated WordPress site to perfection.

2. Set Up Effective Caching (Object, Page, CDN)

If your WordPress website gets a decent amount of traffic, you should consider implementing caching at multiple levels: object caching (like Redis or Memcached) for database queries, page caching for static HTML versions of your pages, and a CDN to offload assets.

Multi-Layer Caching Strategy:

Object Caching (Redis/Memcached):
- Stores request:database results in memory
- Reduces database load by 60–80%
- Speeds up dynamic content generation
- Essential for database-heavy sites
Page Caching:
- Caching involves saving the data, or pre-rendered content of a page, so that the server does not need to recreate it anew for each visitor.
- Generates non-dynamic HTML files from dynamic Web sites.
- Reduces PHP processing by 70–90%
- Compatible with plugins such as WP Rocket, W3 Total Cache
Browser Caching:
- Caches static assets in visitors’ browsers locally
- Reduces repeat download requests
- Improves return visitor experience
- Set via .htaccess or server configuration

CDN Usage: Distribute your static assets across a global network to reduce latency and server load. When a visitor accesses your site, assets are served from the nearest CDN node instead of your main server, ensuring faster load times and lower bandwidth usage. You can easily integrate your Cloudflare account with ServerAvatar.