Slow page load times hurt your WordPress site‘s user experience and search engine visibility. As a website owner with over 15 years of experience, I often see render-blocking resources as a key culprit.
Let me walk you through what causes render-blocking JS and CSS issues, and share fixes that actually work…
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Why You Need to Fix Render-Blocking Resources
Render-blocking JavaScript and CSS prevents the browser from displaying page content until these files are loaded and executed.
This delays the time to first render, also called Time to First Byte (TTFB). Studies show higher TTFB leads to higher bounce rates:
[Insert image with TTFB stats]High TTFB also negatively impacts user experience metrics like Speed Index and Largest Contentful Paint.
Now you may be wondering – how much of an impact do render-blocking resources actually have on TTFB?
Based on HTTP archive data, the average Time To First Byte (TTFB) for WordPress sites is 1.9 seconds on mobile and 1.1 seconds on desktop.
Of this, JavaScript accounts for nearly 50% of the delay on mobile:
[Insert pie chart showing JS delay contribution to TTFB]Clearly, render-blocking JavaScript has a huge bearing on TTFB and user experience. By optimizing delivery of these resources, you can significantly boost site speed.
Now let‘s get into how you can start fixing render-blocking requests for your WordPress site…
Detecting Render-Blocking Resources on Your Site
Before optimizing, you need to find out which scripts and stylesheets are blocking rendering on your pages.
Some easy ways to detect render-blocking resources:
1. PageSpeed Insights: Check the "Eliminate render-blocking resources" recommendation. It lists all blocking CSS/JS files.
2. Chrome DevTools: In the Network panel, look for CSS/JS requests with a ‘Blocking‘ label in the ‘Waterfall‘.
3. WebPageTest: The filmstrip view will highlight any rendering delays caused by blocking assets.
Analyze a few key pages like your homepage and category archives to uncover common render-blocking requests. This will give you a starting point for optimizations.
Now let‘s look at the optimization strategies you can follow…
5 Ways to Fix Render-Blocking Resources in WordPress
Over the years, I‘ve found these to be the most effective ways to minimize render-blocking requests on WordPress sites:
1. Use Caching Plugins
Caching plugins like WP Rocket can automatically condense CSS/JS files and fix render blocking issues.
Key features to leverage:
- CSS/JS minification to reduce file sizes
- Concatenation to combine multiple files
- Async/deferred JS loading for non-critical scripts
With WP Rocket, I was able to reduce requests on a site from 63 to just 7 and improve Speed Index by 35%!
2. Load Only Critical CSS Above the Fold
Prioritize loading CSS required to render above-the-fold content first.
You can inline critical CSS directly in the <head>. I recommend using WP Critical CSS plugin which generates optimized critical CSS for your theme.
This reduces the amount of CSS delaying initial render.
3. Delay Non-Essential JavaScript
Defer or asynchronously load non-critical JS files that don‘t impact core UX:
<script async src="non-critical-script.js"> </script>I typically defer analytics scripts, video players, social sharing buttons etc. to speed up rendering.
4. Reduce Requests from Plugins/Themes
A typical WordPress site uses 35+ plugins, many with heavy scripts that block rendering.
Review your plugins and switch to lighter alternatives when possible. Also deactivate and remove any unused plugins.
The same applies for themes. Switch to a well-optimized theme like Astra with fewer resource demands.
5. Optimize Browser Caching
Enabling caching minimizes requests for repeat visitors.
Set optimal cache lifetimes for static assets through browser caching plugins. I recommend Cache Enabler.
On one site, I reduced repeat resource requests by 65% using optimal browser caching headers!
Diagnosing and Troubleshooting Render-Blocking Issues
Still seeing render-blocking resources on your WordPress site after optimizations? Here are a few tips to help troubleshoot:
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Check using WebPageTest filmstrips to pinpoint any delays in page rendering due to script/stylesheet loading.
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Use Chrome DevTools Coverage tab to uncover unused CSS that can be removed.
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Enable script/stylesheet logging in browser DevTools to analyze each file and determine criticality.
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Test disabling plugins one-by-one to find conflicts causing extra resource loading.
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Speak to your developers to lazy load non-critical JS selectively through code optimizations.
With some trial-and-error, you can troubleshoot which specific resources are blocking rendering on your WordPress site.
Key Takeaways
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Render-blocking requests can significantly delay Time to First Byte and hurt site speed.
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Use PageSpeed Insights and Chrome DevTools to detect render-blocking CSS/JS.
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Caching plugins like WP Rocket can automatically optimize delivery of rendering resources.
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Load critical CSS inline and delay/defer non-essential JS to speed up rendering.
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Minimize requests from bloated themes, plugins and enable optimal browser caching.
Hopefully these tips will help you speed up page rendering by eliminating render-blocking requests on your WordPress site. Let me know if you have any other questions!
