If your WordPress website has a “Eliminate render-blocking resources” warning in Google PageSpeed Insights, some CSS or JavaScript files are making the browser wait before it can display the page.
This can delay the first visible content and make the website feel slower, especially on mobile devices.
The good news is that you usually don’t need to remove every CSS or JavaScript file.
The goal is to make the browser load the resources needed to display the visible part of the page first, while loading less important files later.
In this guide, you’ll learn how to identify render-blocking resources in WordPress and fix them without breaking your website.
What Are Render-Blocking Resources?
When a browser receives a webpage, it has to download and process different resources before it can fully render the page.
CSS is especially important because the browser needs to understand the styling before it can safely display the page.
Some JavaScript can also interrupt the browser’s work when it is loaded in a blocking way.
These resources are commonly called render-blocking resources.
Typical examples include:
- CSS stylesheets
- JavaScript files
- Theme CSS
- Plugin CSS
- JavaScript libraries
- Font files
- Third-party scripts
Not every resource is a problem.
The real issue is when resources that aren’t necessary for the initial view prevent the browser from displaying important content quickly.
How Do You Find Render-Blocking Resources?
Start with Google PageSpeed Insights.
Enter the URL you want to test and look through the performance opportunities.
You may see a recommendation related to:
Eliminate render-blocking resources
The report normally identifies files that are delaying rendering.
You can also use Chrome DevTools to inspect the page and see which CSS and JavaScript files are being loaded.
Don’t immediately remove a file just because it appears in the report.
First determine:
- What plugin loads it?
- What theme feature uses it?
- Is it required above the fold?
- Is it needed on this particular page?
- Can it be deferred?
- Can it be loaded later?
That information makes optimization much safer.
1. Defer Non-Critical JavaScript
One of the simplest ways to deal with blocking JavaScript is to defer scripts that aren’t required to render the initial page.
With deferred loading, the browser can continue parsing the HTML instead of stopping to execute the script immediately.
This is particularly useful for scripts that don’t control the first visible part of the page.
Examples include:
- Analytics
- Tracking scripts
- Social widgets
- Some sliders
- Chat tools
- Marketing scripts
- Other non-critical functionality
Many WordPress performance plugins provide a setting to defer JavaScript automatically.
After enabling it, test your website carefully.
Some scripts are required for menus, forms, popups, checkout, and other features. If those scripts are delayed incorrectly, parts of the website may stop working.
2. Delay JavaScript That Isn’t Needed Immediately
Deferring JavaScript and delaying JavaScript are related, but they aren’t exactly the same.
With JavaScript delay, scripts can be held back until the browser has completed more important work or until the visitor interacts with the page.
This can reduce the amount of JavaScript running during the initial loading period.
Scripts that are often candidates for delay include:
- Analytics
- Heatmaps
- Chat widgets
- Advertising scripts
- Social media scripts
- Marketing trackers
However, don’t delay everything blindly.
If a script is responsible for a critical feature, it may need to load earlier.
3. Remove Unused CSS
CSS can become a major source of unnecessary work on WordPress websites.
Themes and plugins sometimes load large stylesheets even when only a small portion of the CSS is needed on a particular page.
For example, a form plugin may load its CSS across your entire website even though the form appears on only one page.
Removing unused CSS can reduce the amount of data the browser needs to process.
Some WordPress optimization tools can automatically identify and remove CSS that isn’t required for the current page.
Test carefully after enabling this type of optimization.
If important CSS is removed, you may see:
- Broken layouts
- Incorrect spacing
- Missing buttons
- Unstyled menus
- Mobile design problems
Always check important pages after changing CSS optimization settings.
4. Load Critical CSS First
The browser doesn’t need every CSS rule immediately.
It mainly needs the CSS required to display the content currently visible on the screen.
This is often called critical CSS.
Critical CSS contains the styles needed for the initial visible portion of the page.
The remaining CSS can be loaded afterward.
This approach allows the browser to start displaying useful content sooner.
Many WordPress performance plugins can generate critical CSS automatically.
If you’re using an optimization plugin, look for features related to:
- Remove unused CSS
- Critical CSS
- Load CSS asynchronously
- Optimize CSS delivery
The exact implementation varies between plugins.
5. Minify CSS and JavaScript
Minification removes unnecessary characters from CSS and JavaScript files.
This can reduce file size by removing things such as:
- Extra spaces
- Line breaks
- Comments
- Formatting characters
Smaller files can be transferred more quickly.
However, minification isn’t a complete solution for render-blocking resources.
A tiny JavaScript file can still block rendering if it is loaded at the wrong time.
Think of minification as reducing file size, while defer and delay techniques control when the browser processes the file.
Both can be useful.
6. Stop Plugins From Loading Assets Everywhere
This is one of the most overlooked WordPress speed problems.
A plugin may only be needed on one page but still load its CSS and JavaScript across the entire website.
For example:
A contact form plugin might only be required on your contact page.
There is no reason for its assets to load on every blog post if they aren’t being used there.
The same can happen with:
- Gallery plugins
- Slider plugins
- Map plugins
- Form plugins
- Popup plugins
- Booking plugins
- WooCommerce extensions
Where possible, load plugin assets only on pages that use them.
This reduces the number of resources the browser has to download and process.
7. Remove Plugins You Don’t Need
If a plugin isn’t providing useful functionality, consider removing it.
Don’t keep plugins simply because you installed them months ago and might use them later.
Review your active plugins and look for:
- Duplicate functionality
- Old features
- Unused widgets
- Unnecessary tracking tools
- Plugins replaced by another solution
- Features that could be handled without a plugin
Reducing unnecessary plugins can simplify the entire website.
However, don’t judge a plugin purely by its presence.
A well-coded plugin may have little performance impact, while a single poorly optimized feature can add a large amount of CSS or JavaScript.
Always look at what the plugin actually loads.
8. Reduce Third-Party JavaScript
Third-party scripts are another common source of blocking resources.
Your website may load code from services such as:
- Google Analytics
- Google Tag Manager
- YouTube
- Live chat
- Advertising platforms
- Heatmap tools
- Review platforms
You don’t necessarily need to remove these services.
Instead, ask whether they need to load immediately.
If a script isn’t required for the visitor to see or use the page, delaying it may be a better solution.
Also remove third-party tools you no longer use.
Every additional service adds another dependency to your website.
9. Optimize Google Fonts
Fonts can also affect the loading process.
If your website uses several font families and weights, the browser may need to download multiple files.
For example, you might have:
- Regular
- Medium
- Semi-bold
- Bold
- Italic
- Another font family
If your design only needs two or three weights, remove the others.
You can also consider hosting fonts locally instead of relying on external font requests.
The goal is simple:
Load only the fonts your design actually needs.
10. Be Careful With Page Builders
Page builders make website design easier, but they can introduce additional CSS and JavaScript.
This is particularly noticeable on pages containing many widgets and effects.
Look at your pages and remove features that don’t add meaningful value.
Common examples include:
- Multiple sliders
- Animated backgrounds
- Complex carousels
- Excessive entrance animations
- Video backgrounds
- Decorative widgets
- Unnecessary interactive elements
You don’t have to abandon your page builder.
A simpler page built with the same builder can often load much more efficiently.
11. Use a Good WordPress Caching and Optimization Setup
A proper WordPress performance setup can handle many of these optimizations automatically.
Useful features include:
- Page caching
- CSS optimization
- JavaScript minification
- JavaScript defer
- JavaScript delay
- Unused CSS removal
- Lazy loading
- Browser caching
- Font optimization
The important part is configuration.
Installing a performance plugin doesn’t automatically make every website fast.
For example, enabling aggressive JavaScript delay without testing can break important website functionality.
Change settings carefully and test after each major change.
If you want to improve your overall WordPress performance rather than only fixing one PageSpeed warning, your WordPress speed optimization service can be used as a broader reference for the type of optimization involved.
12. Use Cloudflare to Improve Resource Delivery
A CDN can help deliver static resources more efficiently to visitors in different locations.
Cloudflare can cache and deliver resources closer to users while also providing other performance features.
However, a CDN doesn’t automatically remove render-blocking behavior.
If your website sends unnecessary CSS or JavaScript, the CDN will simply deliver those files faster.
You still need to control what the browser loads and when it loads it.
For more information, see our guide on using Cloudflare with WordPress.
13. Don’t Combine Every CSS and JavaScript File
Older WordPress optimization advice often recommends combining every CSS and JavaScript file into a single file.
That isn’t always the best solution today.
Combining files can sometimes create a larger file containing code that isn’t needed on a particular page.
Instead, focus on:
- Removing unused code
- Loading assets only where required
- Deferring non-critical JavaScript
- Delaying third-party scripts
- Optimizing CSS delivery
The goal isn’t to have the smallest number of files.
The goal is to deliver the right resources at the right time.
14. Fix Render-Blocking Resources Without Breaking the Website
Performance optimization should never be done at the expense of functionality.
After changing CSS or JavaScript settings, test:
- Main navigation
- Mobile menu
- Contact forms
- Search
- Login
- Popups
- Buttons
- Sliders
- WooCommerce cart
- Checkout
- Product filters
If you run an online store, JavaScript optimization deserves extra attention because WooCommerce functionality can depend on several scripts.
You can also review your WooCommerce performance resources when optimizing an online store.
15. Check Your Core Web Vitals
Render-blocking resources can affect several aspects of loading performance.
After optimization, check your:
- Largest Contentful Paint
- Interaction to Next Paint
- Cumulative Layout Shift
- First Contentful Paint
- Total Blocking Time
Don’t focus only on the PageSpeed score.
A website can have a high score but still have a poor experience for real visitors.
Your goal should be a website that loads important content quickly and responds properly when people interact with it.
16. Don’t Ignore Total Blocking Time
If you’re removing render-blocking JavaScript, you may also improve Total Blocking Time.
TBT measures the amount of time the browser is occupied with long tasks during loading.
Reducing unnecessary JavaScript can therefore help with both problems.
If you’re dealing with high TBT as well, see our guide on how to reduce Total Blocking Time in WordPress.
17. Optimize the Entire Page, Not Just One Warning
PageSpeed Insights may show several recommendations at the same time.
For example, you might see:
- Eliminate render-blocking resources
- Reduce unused JavaScript
- Reduce unused CSS
- Avoid enormous network payloads
- Properly size images
- Serve images in next-generation formats
- Minimize main-thread work
These recommendations can be connected.
Reducing unnecessary JavaScript can help with multiple issues at once.
The same applies to reducing oversized images and unnecessary CSS.
Don’t treat every warning as a completely separate problem.
Look at the underlying cause.
A Simple Render-Blocking Optimization Checklist
If you want a quick process to follow, use this checklist:
- Test the page with PageSpeed Insights
- Identify the blocking CSS and JavaScript
- Defer non-critical JavaScript
- Delay scripts that aren’t needed immediately
- Remove unused CSS
- Generate critical CSS where appropriate
- Minify CSS and JavaScript
- Prevent plugins from loading assets unnecessarily
- Remove unused plugins
- Reduce third-party scripts
- Reduce unnecessary font files
- Simplify page-builder elements
- Enable sensible caching
- Use a CDN
- Test mobile pages
- Check forms, menus, and other interactive features
- Re-test PageSpeed Insights
What Is the Best Way to Eliminate Render-Blocking Resources?
There isn’t one setting that fixes every WordPress website.
The best approach is to first identify which resources are actually blocking the page.
Then:
Remove what isn’t needed.
Defer what isn’t urgent.
Load critical CSS early.
Delay third-party scripts when possible.
Load plugin assets only where they’re required.
This gives the browser less work to do during the most important part of page loading.
Will Eliminating Render-Blocking Resources Make WordPress Faster?
It can.
When unnecessary CSS and JavaScript stop delaying the initial rendering process, the browser can display important content sooner.
But the final improvement depends on what was blocking the page in the first place.
If the main problem is a huge image, slow server, or large JavaScript application, fixing render-blocking resources alone won’t solve everything.
That’s why a complete performance audit is often more useful than focusing on a single PageSpeed recommendation.
Frequently Asked Questions
What are render-blocking resources in WordPress?
Render-blocking resources are files such as CSS and JavaScript that can delay the browser from displaying the webpage. They become a problem when non-critical files are loaded before important visible content.
How do I fix render-blocking JavaScript in WordPress?
Start by identifying the scripts causing the warning. Then defer or delay non-critical JavaScript, remove unnecessary scripts, and prevent plugins from loading JavaScript on pages where it isn’t needed.
How do I fix render-blocking CSS?
You can reduce unused CSS, generate critical CSS, minify stylesheets, and load non-critical styles later when appropriate.
Should I defer all JavaScript?
No. Some JavaScript is required for important website functionality. Defer or delay non-critical scripts while testing menus, forms, checkout, search, and other interactive features.
Does a caching plugin remove render-blocking resources?
A good optimization plugin can provide settings that help reduce render-blocking CSS and JavaScript, but the result depends on how the website is configured.
Does Cloudflare fix render-blocking resources?
Cloudflare can improve resource delivery and caching, but it doesn’t automatically remove unnecessary CSS or JavaScript. Those resources still need to be optimized.
Can render-blocking resources affect Core Web Vitals?
Yes. Resources that delay rendering can contribute to slower loading metrics, particularly when they prevent important content from appearing quickly.
Final Thoughts
Render-blocking resources are not automatically bad.
Your website needs CSS and JavaScript to work properly.
The problem starts when the browser is forced to process non-essential resources before displaying important content.
Start by finding the files responsible. Remove unnecessary assets, reduce unused CSS, defer non-critical JavaScript, delay third-party scripts, and make sure plugins aren’t loading resources everywhere.
Then test the website again.
The goal isn’t to eliminate every CSS or JavaScript file.
The goal is to make the browser load the right resources at the right time.