In this Google PageSpeed Experiment, we’re testing W3 Total Cache’s Remove CSS/JS feature to understand its impact on website performance.
Our goal is to assess how this specific feature influences website speed.
Control Website
On our Control website we installed WordPress and the following plugins:
- Contact Form 7
- Molongui Authorship
- My Calendar
- Newsletter
- Photo Gallery
- Poll
- Social Media and Share Icons (Ultimate Social Media)
- TablePress
- WordPress Related Posts Thumbnails
Control Website: https://wordpress-speed-test.com/03212024-a-before/
Experimental Website
With our experimental website, we installed WordPress with the same plugins as our Control Website.
We also installed W3 Total Cache Pro and configured the Remove CSS/JS features.
Experimental Website: https://wordpress-speed-test.com/03212024-a-after/
Experimental Website Changes
WordPress plugins often load CSS and JavaScript files, even on pages where they’re unnecessary.
For instance, on our Control Website, the Contact Form 7 plugin adds CSS and JavaScript to the homepage, although no contact form is present.
This extra, unused CSS and JavaScript are called ‘bloat’ and can slow down your website unnecessarily.
To address this, on our Experimental Website, we removed many of these unnecessary CSS and JavaScript files from the homepage.
In the screenshot below, you’ll notice that we’ve removed some scripts and styles from our homepage. For instance, we don’t have a poll running on our homepage, so we don’t need the associated scripts. They’re unnecessary clutter, so we got rid of them.
How the test was run
We conducted six tests on each website using the Google PageSpeed test and averaged all the scores.
-34% Potential
Savings from
Unused
JavaScript
In this test, removing unused CSS and JS changed the Potential Savings From Unused JavaScript from 127.5 KiB to 84 KiB. Read the documentation to learn how you can remove unused CSS and JS.
Upgrade to W3 Total Cache Pro and improve your PageSpeed Scores today!
Test results
Desktop Mobile
Performance
Performance score
| Standard site | W3TC Optimized | Difference |
|---|
| 57.17 | 84.67 | +27.5 | +48.1% |
| | |
Points per Metrics
First Contentful Paint
| Standard site | W3TC Optimized | Difference |
|---|
| 0.17 points | 8 points | +7.83 points | +4700% |
| | |
Largest Contentful Paint
| Standard site | W3TC Optimized | Difference |
|---|
| 3.17 points | 17 points | +13.83 points | +436.84% |
| | |
Total Blocking Time
| Standard site | W3TC Optimized | Difference |
|---|
| 30 points | 30 points | 0 points | 0% |
| No change. |
Cumulative Layout Shift
| Standard site | W3TC Optimized | Difference |
|---|
| 22.5 points | 22.5 points | 0 points | 0% |
| No change. |
Speed Index
| Standard site | W3TC Optimized | Difference |
|---|
| 1 points | 7.67 points | +6.67 points | +666.67% |
| | |
Metrics
First Contentful Paint
| Standard site | W3TC Optimized | Difference |
|---|
| 3.72 s | 1.12 s | -2.6 s | -69.96% |
| | |
Largest Contentful Paint
| Standard site | W3TC Optimized | Difference |
|---|
| 4.78 s | 1.88 s | -2.9 s | -60.63% |
| | |
Total Blocking Time
| Standard site | W3TC Optimized | Difference |
|---|
| 1.67 ms | 0 ms | -1.67 ms | -100% |
| | |
Cumulative Layout Shift
| Standard site | W3TC Optimized | Difference |
|---|
| 0.07 | 0.07 | 0 | 0% |
| No change. |
Speed Index
| Standard site | W3TC Optimized | Difference |
|---|
| 4.58 s | 1.73 s | -2.85 s | -62.18% |
| | |
Diagnostics
Largest Contentful Paint element
| Standard site | W3TC Optimized | Difference |
|---|
| 4783.33 ms | 1895 ms | -2888.33 ms | -60.38% |
| | |
Potential savings from render-blocking resources
| Standard site | W3TC Optimized | Difference |
|---|
| 4891.67 ms | 630 ms | -4261.67 ms | -87.12% |
| | |
Potential savings by serving images in next-gen format
| Standard site | W3TC Optimized |
|---|
| Passed audit | Passed audit |
Time third-party code blocked the main thread for
| Standard site | W3TC Optimized | Difference |
|---|
| 0 ms | 0 ms | 0 ms |
| No change. |
Potential savings from unused CSS
| Standard site | W3TC Optimized |
|---|
| 59.17 KiB | Passed audit |
Potential savings from unused JavaScript
| Standard site | W3TC Optimized | Difference |
|---|
| 127.5 KiB | 84 KiB | -43.5 KiB | -34.12% |
| | |
Potential savings if Minifying CSS
| Standard site | W3TC Optimized |
|---|
| 3 KiB | Passed audit |
# of static assets without an effecient cache policy
| Standard site | W3TC Optimized | Difference |
|---|
| 53 | 20 | -33 | -62.26% |
| | |
JavaScript execution time
| Standard site | W3TC Optimized | Difference |
|---|
| 0 s | 0 s | 0 s |
| No change. |
Main-thread work
| Standard site | W3TC Optimized | Difference |
|---|
| 0.43 | 0.28 | -0.15 | -34.62% |
| | |
# of long main-thread tasks
| Standard site | W3TC Optimized |
|---|
| 1 | Passed audit |
Initial server response time
| Standard site | W3TC Optimized | Difference |
|---|
| 396.67 ms | 393.33 ms | -3.33 ms | -0.84% |
| | |
# of large layout shifts
| Standard site | W3TC Optimized | Difference |
|---|
| 1.5 | 1.5 | 0 | 0% |
| No change. |
# of user timings
| Standard site | W3TC Optimized |
|---|
| Passed audit | Passed audit |
# of animations found
| Standard site | W3TC Optimized |
|---|
| Passed audit | Passed audit |
