Impact of WordPress Plugins on Site Load Speed – A Case Study

What is the Impact of WordPress Plugins on Site Load Speed ?

Impact of WordPress Plugins on Site Load SpeedSometimes, we get so busy in optimizing our clients’ site for speed that we completely forget our own website. We tend to forget that WordPress updates keep coming at frequent intervals, we forget that WordPress plugin updates also keep coming at frequent intervals and we also forget that rules of Internet keeps changing rapidly. We install WordPress plugins, activate it and start using these plugins without giving any thought about the impact of WordPress Plugins on Site Load Speed. We assume that everything is perfect on our site, which becomes one of our biggest mistakes behind the slowdown of our websites.

In fact, using the word “Forget” would be wrong, the right word would be “Ignorance.” We simply ignore that the site was optimized for speed quite a long time back, but in the light of all the fresh updates launched in the meantime, the older site speed optimization techniques may not work, or may require some fresh site speed re-optimization techniques to get the site back on the speed track.

Set Good Examples Before Making Any Commitment to Your Clients

“Practice what you preach” is an old idiom, but fits perfectly even today in a number of scenarios. Before moving any further, I would like to share a very important observation that I noticed a couple of days back. One of our clients named Brent Mitchell made a remark on WP Engine after looking at their site. Let me recap his comment in his own words.

Hell, WP Engine scores horribly when it comes to page speed tests… How can they fix all that for clients when they don’t even do it themselves. – Brent Mitchell

The client made this remark on account of GTmetrix site speed test report of WP Engine site.WP Engine site speed test on GTmetrix

Looking at this GTmetrix site speed test report, we can say that the client was not wrong in his own perception. Although, he did switched his site to WP Engine, but he wanted to assure himself that it was worth the switch. He also wanted to ensure that he was going in safe hands while choosing WP Engine as site host. The above mentioned remark triggered like an eye opener to us. It has been a long time that I had looked back at my own website. Gosh!!! All the time, I was working hard and got so busy optimizing my clients’ site for speed that my own site was completely ignored.

Step 1 : Create a List of All the WordPress Plugins Active on Your Site

My site is also hosted on WP Engine as I understand the importance of web host servers for site speed optimization. At least, I don’t need to worry about CPU Throttling as implemented in Bluehost shared hosting accounts. I just wanted to recheck my site speed test reports so that none of my clients can point a finger back at us and leave similar remarks one day. I started looking at the list of WordPress Plugins that were used on my WP Engine site installation and made an entire list of active plugins.

Take Initial Site Speed Test Reports For Creating Your Own Yardstick

My site on WP Engine was using all the above mentioned 12 WordPress Plugins. As in our other site speed optimization case studies, before moving any further, a site speed test diagnosis is required on the first hand. It helps us detect the bottlenecks pulling the site speed down. Let us have a look at some of the site speed test reports retrieved after testing the site on some of the most prominent online site speed testing tools.

GTmetrix Site Speed Test Report Before Optimization

GTmetrix site speed report without WordPress PluginsPage Speed Grade : (89%) B

YSlow Grade : (79%) C

Page load time : 1.14s

Total page size : 579KB

Total number of requests : 55

Pingdom Tools Site Speed Test Report Before Optimization

Pingdom Speed Test before optimization

Page size : 563.7kB

Load time : 843ms

Requests : 61

Perf. grade : 78/100

Your website is faster than 92% of all tested websites

Webpagetest Site Speed Test Report Before Optimization

Webpagetest site speed test before optimizationFirst Byte Time : B
Keep-alive Enabled : A
Compress Transfer : A
Compress Images : B
Progressive JPEGs : B
Cache static content : B
Effective use of CDN : X

First View : 1.803s
Repeat View : 0.764s

Webhostinghero Site Speed Test Report Before Optimization

webshostinghero site speed test before optimizationGrade : C

Score : 79%

Load Time : 1.24 sec

First Byte : 0.09 sec

Number of Requests : 55

Page Size : 779.9 kb

Load Impact Site Speed Report

Step 2 : Create a Development Site to Analyze the Impact of WordPress Plugins

Staging is one of the best features offered by WP Engine. It helps us create a development environment with One Click Staging Area. It creates a clone of the production site so that we can safely test our plugins or updates on the staging site before pushing any change to the live production site. Staging site offers a risk free development environment so that we can test the site with any plugin or updates before pushing it to the production site.

Step 3 : Deactivate All the WordPress Plugins to Study Site Behavior

All the plugins were deactivated on the staging site in order to take our first site speed test reports. Different plugins impose different set of resource requirements. Depending on the required set of resources, every plugin has some overhead associated with it; due to which site slows down. Also remember that now we are working on staging site which means that no WP Engine caching is active on the site. Let us take some site speed test reports without activating any plugins on the site. These reports will act as our yardstick to study the impact of WordPress plugins on site load speed.

GTmetrix speed report with plugins inactivePage Speed Grade : (93%) A

YSlow Grade : (90%)

Page load time : 1.40s

Total page size : 307KB

Total number of requests : 43

Pingdom Tools Speed report without plugins

Page size : 324.6kB

Load time : 1.01s

Requests : 48

Perf. grade : 79/100

Your website is faster than 89% of all tested websites

webpagetest speed report without pluginsFirst Byte Time : F
Keep-alive Enabled : A
Compress Transfer : A
Compress Images : B
Progressive JPEGs : B
Cache static content : A
Effective use of CDN : X

First View : 2.802s
Repeat View : 1.411s

Webhostinghero speed report without pluginsGrade : A

Score : 90%

Load Time : 1.97 sec

First Byte : 1.40 sec

Number of Requests : 43

Page Size : 575.3 kb

Step 4 : Diagnose Your WordPress Theme to Fix Theme Related Issues

As you can see, none of the plugins are active on the site so all the reports are green. Looking at the GTmetrix site speed test report, we see some problems with a couple of icon files used by our theme.

Specify image dimensions E (50)Specify Image Dimensions score 50 pulling site speed down

Let us try to find the solutions one by one. The theme developers MySiteMyWay have not defined the image size for icons because the images can be used either in the size of 32px or 16px. We tried to find an easy solution for it and got it working too. The easiest fix is to save the images to local and then upload these images from local to WordPress one by one.

We took fresh GTmetrix site speed test report. You can see that the results are better.

Specify image dimensions C (70)GTmetrix report after fixing image dimension issue

We have improved the value of Specify image dimensions from E (50) to C (70).

Now, we are left with only one problem –

The following image(s) are missing width and/or height attributes. (Dimensions: 1 x 1) (6 uses)

We tried to find the solution for this problem by raising a support ticket with MySiteMyWay, but no solution yet. We were left with no other choice than to leave it as it is and move ahead to improve other site speed optimization factors.

Step 5 : Move Development Site From Staging to Live

After making all the above mentioned changes, we moved the site from Staging to Live.

Let us have a fresh GTmetrix site speed test report on live site.GTmetrix speed report on live site

As you can see, merely by making some small changes, we have achieved some improvement in our GTmetrix site speed test report.

Step 6 : Remove WordPress Plugins One by One For Site Speed Optimization

Let us start removing all the WordPress plugins one by one. It will help us check whether we can improve our site load time any further.

  • WP Socializer was removed. ( Now, we are using JetPack module socializing for our posts. )
  • Social Comments. ( The entire system was replaced with Google+ Comments Widget )
  • Autoptimize plugin was also removed. (Autopotimize is a great plugin and I love it, but it was not required at this time.)
  • Google Analytics code was also removed. Instead of implementing Google Analytics, I prefer JetPack Stats as it works much better and also allows me watch the stats straight from my site without adding any other WordPress plugin.

We also did some fine tuning to some of the active plugins in order to improve site load speed.

Step 7 : Configure .htaccess File to Optimize Site for Speed

Some changes were also made in .htaccess file

<ifModule mod_php5.c>
php_value zlib.output_compression on

<IfModule mod_deflate.c>
<IfModule mod_filter.c>
AddOutputFilterByType DEFLATE text/plain text/html application/x-httpd-php-source
AddOutputFilterByType DEFLATE text/xml application/xml application/xhtml+xml application/xml-dtd
AddOutputFilterByType DEFLATE application/rdf+xml application/rss+xml application/atom+xml image/svg+xml
AddOutputFilterByType DEFLATE text/css text/javascript application/javascript application/x-javascript
AddOutputFilterByType DEFLATE font/truetype application/x-font-ttf font/opentype application/x-font-otf

<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg “access 1 year”
ExpiresByType image/jpeg “access 1 year”
ExpiresByType image/gif “access 1 year”
ExpiresByType image/png “access 1 year”
ExpiresByType text/css “access 1 month”
ExpiresByType text/html “access 1 month”
ExpiresByType application/pdf “access 1 month”
ExpiresByType text/x-javascript “access 1 month”
ExpiresByType application/x-shockwave-flash “access 1 month”
ExpiresByType image/x-icon “access 1 year”
ExpiresDefault “access 1 month”

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# END WordPress

Let us have some fresh page speed test reports to witness any site speed improvement achieved so far.

Step 8 : Diagnose Fresh Site Speed Test Reports for Site Speed Optimization

GTmetrix Site Speed Test Report

GTmetrix speed report with minimal pluginsPage Speed Grade : (97%) A

YSlow Grade : (90%)

Page load time : 0.89s

Total page size : 331KB

Total number of requests : 44

Pingdom Tools Speed Report with minimal plugins activePage size : 348.9kB

Load time : 526ms

Requests : 48

Perf. grade : 75/100

Your website is faster than 96% of all tested websites

Webpagetest speed report with minimal plugins activeFirst Byte Time : A
Keep-alive Enabled : A
Compress Transfer : A
Compress Images : B
Progressive JPEGs : B
Cache static content : A
Effective use of CDN : X

First View : 1.216s
Repeat View : 0.756s

Webhostinghero speed report with minimal pluginsGrade : B

Score : 89%

Load Time : 1.07 sec

First Byte : 0.09 sec

Number of Requests : 44

Page Size : 517.4 kb

Google PageSpeed Insights site speed report

Step 9 : Analyze and Fix All the Speed Related Issues Caught in Speed Test Reports

GTmetrix site speed test report is showing some areas of concern.

Minify CSS : A (91)
Serve scaled images A : (92)
Minify JavaScript A : (95)GTmetrix Speed Report with Problematic Areas

We did some more tweaking to get these site speed factors better in order to improve the site speed results.

Serve scaled images : A (100)
Minify JavaScript : A (99)
Minify CSS A : (93) [It could be made better by further tweaking the plugins, but we decided to leave it as it is.]GTmetrix Speed reports improved

Step 10 : Take Fresh Site Speed Test Reports After Optimizing The Site For Speed

Let us have fresh site speed optimization test reports to compare the achieved site speed improvements with our tweaking and configuration changes.

Final GTmetrix Speed Report Page Speed Grade : (96%) A

YSlow Grade : (90%) A

Page load time : 0.66s

Total page size : 298KB

Total number of requests : 42

Final Pingdom Tools Speed ReportPage size : 315.1kB

Load time : 334ms

Requests : 47

Perf. grade : 95/100

Your website is faster than 99% of all tested websites

Final Webpage test speed reportFirst Byte Time : A
Keep-alive Enabled : A
Compress Transfer : A
Compress Images : B
Progressive JPEGs : A
Cache static content : A
Effective use of CDN : X

First View : 1.216s
Repeat View : 0.713s

Webhostinghero site speed final reportGrade : B

Score : 88%

Load Time : 1.09 sec

First Byte : 0.10 sec

Number of Requests : 44

Page Size : 503.9 kb

Load Impact Report Case Study

Google PageSpeed Insights Final Report

Comparative Analysis to Study the Impact of WordPress Plugins on Site Load Speed

Comparative Analysis of GTmetrix Site Speed Factors

Factor Before Optimization After Optimization Result Gain
Page Speed Grade 89% (B) 96% (A) Improved 08%
YSlow Grade 79% (C) 90% (A) Improved 14%
Page load time 1.14 s 0.66 s Improved 42%
Total page size 579 Kb 298 kB Improved 49%
Total number of requests 55 42 Improved 24%

Values of Page Speed Grade, YSlow Grade, Page load time, Total page size as well as Total number of requests improved.

Comparative Analysis of Pingdom Tools Site Speed Factors

Factor Before Optimization After Optimization Result Gain
Page Size 563.7 kB 315.1 kB Improved 44%
Load time 843 ms 334 ms Improved 60%
Requests 61 47 Improved 23%
Perf. Grade 78/100 95/100 Improved 22%

Your website is faster than 99% of all tested websites. [Earlier: Your website is faster than 92% of all tested websites.]

Values of Page size, Load time, Requests and Perf. Grade improved.

Comparative Analysis of Webpagetest Site Speed Factors

Factor Before Optimization After Optimization Result
First Byte Time B A Improved
Keep-alive Enabled A A Neutral
Compress Transfer A A Neutral
Compress Images B B Neutral
Progressive JPEGs B A Improved
Cache static content B A Improved
Effective use of CDN No No Neutral
First View 1.803 s 1.216 s Improved
Repeat View 0.764 s 0.713 s Improved

Comparative Analysis of Webhostinghero Site Speed Factors

Factor Before Optimization After Optimization Result Gain
Grade A B Deteriorated NA
Score 90% 88% Deteriorated 02%
Load Time 1.97 sec 1.09 sec Improved 45%
First Byte 1.40 sec 0.10 sec Improved 93%
Number of Requests 43 44 Deteriorated 02%
Page Size 575.3 kb 503.9 kb Improved 13%


Now, everything on the site seems to be fixed. Sometimes, even the best of the best may get the things wrong after adding new plugins to the site. Problem is not behind adding new plugins, but the problem is in the ignorance of testing site speed after addition of new plugins as some plugins may have adverse effects on the site load time. Now, our site is fully optimized, running at full throttle by using some of the best plugins, best configurations and best site speed optimization by Mark de Scande. You can hire my Page Speed Optimization Services at UpWork for your commercial projects.

In our next case study, we are planning to test WP Engine with a test CDN in order to understand the site speed behavior after activating CDN on it.

Website Speed Optimization Case Study Details
Website –
Web Host Server – WP Engine
Site Speed Optimizer – +Mark de Scande
Editor – +Ashutosh Kasera


WordPress Site Speed Expert, Speeding up WordPress sites across the Globe

I am the fuel behind the high speed of innumerable fast running wordpress websites hosted either on a cheap server or a dedicated server.
Today, Speed is a matter of great concern, and I don't only optimize but re-energize. I am also a lifetime WPMU Dev member.

One of the largest free blogging websites BlogLines in South Africa is my baby. I not only conceived the idea of free blogging in South Africa, but also implemented it with an objective of adding a new dimension to the world of free blogging. Blogging helps us in enhancing the quality of our social life by transforming the ways in which we share our ideas and opinions with each other. South Africa blogging environment has never been so easy and user-friendly as it is today.

I have practised and learned all the technical aspects related to WordPress. In the past couple of years, I have developed a wide range of websites using WordPress, WordPress MU and now using the latest WordPress MultiSite.

I am the WordPress Speed Energizer Wiz, and I am always hunting around to find slow running websites. I know, these websites need me in order to live a long and healthy life.
Only the wordpress sites powered with speed, capable of running at full throttle are going to survive in this tough and competitive world of Internet.

Need my help but can not afford my hourly rate buy me coffee and i will do a full report on your website.

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