Why Is My WordPress Slow? (13 Causes Identified By WordPress Experts)

Why Is My WordPress Slow? (13 Causes Identified By WordPress Experts)

One of the most puzzling things I hear all website owners discuss is – Why is my WordPress slow? WordPress speed is undeniably one of the essential topics you need to be aware of when it comes to maintaining a website. In fact, it comes down to one of the top 5 ranking factors for ranking your site on Google SERP.

In 2021, a detailed survey by SEO specialists showed that Google uses more than 200 ranking factors to rank a website. Although some of these factors are controversial, most are proven and make a lot of sense when appropriately implemented.

Suppose, for example – the problem with a slow WordPress website may be with your hosting service provider, the server, an old plugin, unoptimized content (images, videos, GIFs), etc.  And this makes it even more difficult to pinpoint why your WordPress site is slow.

And so, in this article, I will highlight and discuss the factors that make WordPress sites load slowly. Answering questions like ‘why is my WordPress website so slow?’ without prior research is simply impossible as many moving parts require addressing. And so, I will show you how to improve WordPress speed and how you can diagnose the problem.

Causes of Decline In WordPress Speed

Apart from the most apparent cause of WordPress speed decline, which is your hosting provider, there are many other reasons. Here are some highlighted reasons:

  1. Using an outdated version of PHP
  2. Using an old version of WordPress
  3. Using the WordPress admin toolbar
  4. Having excess content on the website
  5. Running too many scripts in the background
  6. Using unnecessary plugins
  7. Using unoptimized plugins
  8. Using an SEO-unoptimized theme
  9. Showing unoptimized images
  10. Uploading unoptimized videos
  11. Using an unoptimized database
  12. Uncached website
  13. Low WordPress memory limit
  14. Low RAM on the server
  15. Slow server response issue

Not following best performance guidelines.

How To Diagnose And Fix A Slow WordPress Website?

Fixing a slow WordPress website is easy but involves many steps. Let’s go through the fixes in a flash:

1. Use the Latest Version of PHP

PHP has come a long way since it launched version 5.0. Moreover, PHP developers improved the language, so you should update your WordPress.

WordPress is built with PHP and offers many advantages, specifically website speed, scalability, security, and performance. For example – Kinsta’s PHP benchmarks show that PHP 8.1 (163 req/sec) can handle more requests than PHP 7.2  (106.56 req/sec). Take a look at the image below:

Resource: Kinsta

Unfortunately, according to a recent study, most site users are still using an older one, and there is a big chance you are in that group. So, it is better to update before it is too late.

Apart from the most apparent cause of WordPress speed decline, which is your hosting provider, there are many other reasons. Here are some highlighted reasons:

  1. Using an outdated version of PHP
  2. Using an old version of WordPress
  3. Using the WordPress admin toolbar
  4. Having excess content on the website
  5. Running too many scripts in the background
  6. Using unnecessary plugins
  7. Using unoptimized plugins
  8. Using an SEO-unoptimized theme
  9. Showing unoptimized images
  10. Uploading unoptimized videos
  11. Using an unoptimized database
  12. Uncached website
  13. Low WordPress memory limit
  14. Low RAM on the server
  15. Slow server response issue

Not following best performance guidelines.

2. Upgrade Your WordPress Version

WordPress developers continuously try to improve the performance of the core WordPress functionalities. Here is a loading time comparison between WP 5.5 to WP 5.9:

WP 5.6
WP 5.7
WP 5.8
WP 5.9
Time first block (ms)
Time to type a character (ms)
Block Selection
Time to select a block (ms)
Inserter Opening
Time to open the global inserter (ms)
Time to type in the inserter search input (ms)
Time to move the mouse between two blocks of items in the inserter (ms)

Source: WordPress

3. Remove Your WordPress Admin Toolbar

WordPress toolbar creates a quick connection between various admin functionalities from the dashboard. You can find it at the top of the page on your WP dashboard.

Although the admin toolbar is convenient for quickly moving between the WP backend and the live site, it also declines your other performance.

To remove the WP admin toolbar, add this shortcode in the functions.php file or follow this image below:

					/* Turn off the WordPress Admin Bar for all users */
add_filter( 'show_admin_bar', '__return_false' );

4. Use WordPress Dashboard Content Restriction

WordPress allows its users to set a limit for the amount of content that will be displayed on the screen. This function allows you to hide the components that streamline your workflow.

Go to the upper-right corner of your dashboard view and click the ‘Screen Options‘ button.

'Screen Options'

In each section, there is a separate Screen Limit Option. For example – the default value is 20.

5. Disable Unnecessary Plugins from Dashboard

WordPress usually carries a lot of pre-installed plugins that people normally prefer not to use. However, these widgets still make external calls which is the reason for performance issues.

To remove these plugins, you can choose to use a free widget disable plugin. Install and activate it, and then go to Appearance > Disable Plugins to disable all unused plugins.

6. Use Query Monitor to Identify Slow Plugins

Are you suspecting that some of your plugins are slowing your site’s performance?

You can monitor the workload of your plugins using a plugin called Query Monitor. It’s free.

Open the plugin interface, go to the ‘Queries by components‘ tab, look for any slow plugins, and delete them.

Most plugins have good alternatives that you can use to get better performance.

7. Use Heartbeat Control

Remember when you see your documents getting autosaved every few seconds on Google Docs whenever you write a doc? Well, it’s a fantastic plugin to use when you don’t want to lose progress while working on large website content.        

The WordPress Heartbeat is a plugin that shows real-time data interaction between your web browser and your server where the site is hosted. It provides a communication protocol between the browser and the server using AJAX calls.

Although autosave and real-time data notifications are crucial, they can slow down your work on the backend. This makes it difficult for other backend functionalities to be quickly executed since AJAX calls block many requests.

Install and activate the plugin, go to Settings > Heartbeat Control Settings, and then choose when settings to reduce or disable. You can enable or disable this setting for different options in your dashboard.

Also, here is the shortcode to disable autosave manually from the functions.php file.

functions disable_autosave() {

Our Suggestion:

Use WP Rocket to control the frequency of autosave requests from the Heartbeat tab on the dashboard. WP Rocket optimizes all the metrics required to improve the Core Web Vitals.

8. Clean and Optimize Your Database

Every WordPress theme in the USA comes with many bloatware that comes in post revisions, transients, etc. Such cases normally occur with WooCommerce stores. So, you’ll have to wait until the problem is a solution.

Normally WooCommerce databases consist of huge data, making cleaning it up essential. This is because unstructured data requires more time to find.

Our Recommendation:

To avoid falling into such situations, use any of the following plugins:

  • WP Rocket
  • WP Database Reset
  • WP-DBManager
  • WP-Optimize
  • WP Reset

9. Use a Caching Plugin

Caching plugins are essential for optimizing and speeding up your database, JavaScript, and CSS files. It also cleans up your CDN and URLs, directly reducing your website’s loading time and the WP admin panel.


If you feel your WordPress backend is working slower than usual, it is time to use caching plugins. Even though you will need to experiment with a few plugins to get the desired result, you will directly notice a sharp change in speed and performance after installing and activating the plugin.

Our Recommendation:

Use any of the following caching plugins for obtaining the best results:

  • WP Rocket
  • WP Super Cache
  • W3 Total Cache
  • WP-Optimize
  • Hummingbird

10. Increase WordPress Memory Limit

It is normal for your WordPress to hit the bottleneck while operating because of a fixed memory limit. For example, this is the default memory limit defined in the WordPress wp-config.php file:

					define('WP_MEMORY_LIMIT, '256'');

In such cases, increasing the memory limit becomes essential and often provides a positive result on doing so.

11. Upgrade RAM for Your Web Server

It is not easy to upgrade your server’s memory limit as your site continues to grow. And the same goes for upgrading RAM on your server as well. In the end, we are all limited by the offers of our hosting service.

If you feel you are being limited by a lower memory and low RAM package that inhibits your site’s growth and performance, then it might be high time to move on to a new and sophisticated hosting provider.

The upgrade plan is easily accessible via the provider’s website or on their social media pages. We recommend hosting your site on an SSD and, of course, using a dedicated high-quality RAM.

12. Examine the Time Required to Process the First Few Bytes

In the 200+ ranking factors used by Google, one factor stresses your website’s overall loading speed. In Google’s PageSpeed Insights, it is referred to as Time To First Byte or TTFB.

The TTFB indicates how long it takes for the first byte to respond from the server after making a request. Deep diving into these packets of information helps you to identify the heavy loads and the delayed responses on your page that can be optimized for scalability and stability.

In Google PageSpeed Insights, you can do a free test to understand and optimize the response time of your site if required. The diagnosis report usually suggests the overall site speed, WordPress loading speed, and interaction time with the server. If you receive a warning in this category, it must be fixed immediately.

Experts recommend that Google prefers TTFB under 200ms. Even more, the Lighthouse audit immediately fails when the browser has to wait for more than 600ms for the server to respond to a data request.

13. Upgrade Your Hosting

This is probably the last solution you were hoping to find. Still, it needs to be done if it is for serving a fast-loading website to your users. In most cases, your hosting plan won’t be enough for your website simply because your site has outgrown its hosting plan.

And ultimately, you and your users will feel the effects of a slow WordPress backend and frontend if it is not addressed quickly and keeps declining. This is when you need to choose a reliable hosting service that provides a customized solution for clients who needs a dynamic package for their website.

Our Recommendation:

Here is a list of hosting services that I found reliable:

  • WP Engine
  • Siteground
  • A2 Hosting
  • Kinsta
  • Fastcomet

Benefits of A Fast WordPress Website

Here are some of the instant benefits of a fast WordPress website:

1. Low Bounce Rate

Blazing website speed is an impression maker when it comes to serving your audience. A study suggests that users lose interest in a site if it requires more than 2 seconds to load. To back up the study, here are some statistics that better explain the fact.

2. Improved Organic Search Ranking

Improved page speed is an impression maker that creates an impression on the client. Fortunately, Google takes it as a positive sign and naturally upgrades its ranking on the Google SERP.

Even though page loading speed isn’t the only important ranking factor, here is a chart that explains the importance of loading speed among other factors that account for ranking on Google.

3. Improved Conversion Rate

Natural boost of the audience to your website will surely improve the conversion rates of your physical and digital products available on the site. Normally, a 2-second delay causes a huge shift in the mindset of the users. Here is an example:

4. Better Mobile Experience

User Interface, user experience, and loading speed – these three factors ensure a better mobile experience for all users around the world. With 61% of all internet users browsing from a mobile phone, Google made it increasingly necessary to optimize your website for mobile.

Frequently Asked Questions (FAQ)

1. Why is WordPress going so slow?

The most obvious reasons for a slow WordPress performance can be defined using two reasons. Firstly, your hosting plan is inadequate for serving your website under the current memory and RAM specifications. And secondly, your WordPress backend is not optimized for caching, not using CDNs, an unoptimized database, etc.

2. How do I fix a slow WordPress site?

The seven basic steps for diagnosing a slow WordPress website are given below:

  1. Investigate your site loading time or Time To First Byte (TTFB)
  2. Delete all the unused and bloated plugins
  3. Optimize your content (Image, Video, Text, GIFs)
  4. Add lazy loading
  5. Implement caching
  6. Implement database optimizer and clean up database
  7. Implement a CDN
3. How can I make WordPress run faster?

Speeding your WordPress website can be done if you follow these eight steps correctly:

  1. Schedule a performance test on Google PageSpeed Insights
  2. Choose an appropriate hosting provider
  3. Update your WordPress, Themes, Plugins, etc.
  4. Use the latest version of WordPress
  5. Remove all redundant and unused plugins
  6. Install lightweight plugins that do not conflict with others
  7. Use a lightweight and SEO-friendly theme
  8. Optimize your content
4. How can I tell what is slowing down my WordPress site?

QUERY MONITOR is the plugin widely used to investigate all the plugins on your WordPress website. Here is how to find the slowest plugins:

  1. Install and activate Query Monitor
  2. Go to ‘Queries By Component’ Tab
  3. Identify your slowest plugins and their loading times.
  4. Use the WP Hive Chrome Extension
  5. Check using GTMetrix Waterfall to find slow plugins and confirm again
5. How do I clean up my WordPress database?

You can clean your WordPress database by following these eight simple steps:

  1. Prevent Spam Comments
  2. Restrict the number of post revisions
  3. Remove all unnecessary plugins and themes
  4. Delete all unused media
  5. Optimize your database tables, i.e., structurize data
  6. Use WP-Optimize to clean your database
  7. Use WP Rocket to speed up the site to database response time
  8. Use a garbage collector for your plugins.


A slow WordPress backend and frontend is a nightmare because retaining your traffic without a fast-loading website is almost impossible. And besides, Google will discourage any site with a low user experience and ultimately de-rank it. So, the sooner you fix these problems, the better.

In addition, implementing some of the diagnosis work like – implementing a CDN, using caching plugins, optimizing your database regularly, updating your WordPress version, etc., will pay tenfolds in Google SERP if done timely and correctly. It will help you to answer the question – ‘why is my WordPress website so slow?’.

Above all, I hope this article supports your actions with enough evidence and knowledge to diagnose a slow WordPress website and pinpoint the problems.

Sharif Hossain Syeed

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