If you have ever run your Divi site through Google PageSpeed Insights and seen a score in the 40s or 50s, you are not alone. Divi is a powerful and flexible page builder, but out of the box it makes no assumptions about how well your images are optimised — and on most sites, images are responsible for 60 to 80 percent of the total page weight.
The good news is that image optimisation is one of the fastest and most impactful things you can do to improve your Divi site's performance. In this guide we will walk through exactly how to diagnose the problem, understand what Google is measuring, and fix it properly without disrupting your Divi layouts or Divi 5 Visual Builder.
Step 1 — Run a PageSpeed Audit
Before you fix anything, you need to know what you are dealing with. Go to Google PageSpeed Insights and enter your homepage URL. Run the test and scroll down to the Opportunities section.
Look for these specific flags:
- Serve images in next-gen formats — means your images are JPEG or PNG rather than WebP
- Properly size images — means images are being loaded at a larger resolution than they are displayed at
- Efficiently encode images — means your images are not compressed enough
- Defer offscreen images — means images below the fold are loading before they are needed
If you see any of these — and on most Divi sites you will see all of them — your images are the primary bottleneck.
Step 2 — Understand What the Scores Actually Mean
Google measures site performance using Core Web Vitals, three specific metrics that directly affect both user experience and search rankings:
Largest Contentful Paint (LCP) measures how long it takes for the largest visible element on the page to load. On most Divi sites this is a hero image or a full-width background. Google considers anything under 2.5 seconds good and anything over 4 seconds poor. A large unoptimised hero image can push your LCP to 6 or 8 seconds on mobile.
Cumulative Layout Shift (CLS) measures visual stability — whether elements jump around as the page loads. Images without defined dimensions contribute to layout shift because the browser does not know how much space to reserve.
Interaction to Next Paint (INP) measures responsiveness. While not directly image-related, a page weighed down with large images loads slower overall, which affects this metric indirectly.
Since 2021 Core Web Vitals have been a confirmed Google ranking factor. A poor PageSpeed score is not just a performance issue — it is an SEO issue.
Step 3 — Audit Your Media Library
Before compressing anything, it helps to understand what you are working with. In your WordPress dashboard, go to Media > Library and switch to list view. You will see all your uploaded images but unfortunately WordPress does not show file sizes by default.
A quick way to audit your images is to install a plugin like Media Cleaner or simply check your hosting file manager. Look for:
- Any JPEG or PNG over 500KB — these should be compressed
- Any image wider than 2400 pixels — most screens do not need anything wider
- Duplicate images that were uploaded multiple times
- Images that are used as Divi section backgrounds at very large sizes
On a typical Divi portfolio or business site you will often find a handful of images accounting for the majority of the total weight.
Step 4 — Compress and Convert to WebP Automatically
Manually compressing images is not sustainable. The real fix is to make compression automatic so every image uploaded in future is handled without you thinking about it.
Divi Image Compressor handles this automatically for every image uploaded through the WordPress media library. It runs locally on your server using PHP's native GD Library or ImageMagick — no API key, no monthly limits, no images leaving your server.
Once installed and activated:
- Go to DiviPerfect > Image Compressor
- Set your compression quality — 80 is recommended for most sites and produces visually identical results at 40 to 60 percent smaller file size
- Enable Convert to WebP — WebP images are 25 to 34 percent smaller than JPEG according to Google's own benchmarks
- Set a Max Width of 2400 pixels — anything wider is unnecessary for web display
- Click Save Settings
From this point on every new upload is automatically compressed, converted, and resized. You never need to think about it again.
Step 5 — Compress Your Existing Media Library
Installing the plugin handles future uploads but you also need to deal with images already in your library. Divi Image Compressor includes a Bulk Compress tool that processes your entire existing media library in one click.
Go to DiviPerfect > Image Compressor, scroll to the Bulk Compress section, and click Compress Existing Images. A progress bar shows you how many images have been processed. On a typical site with 100 to 200 images this takes two to five minutes.
Important: make sure the Enable Image Compression toggle is turned on and saved before running the bulk compressor, otherwise the tool will run but compression will not be applied.
Step 6 — Check Your Divi Image Module Settings
Once your images are compressed and converted to WebP, there are a few Divi-specific settings worth checking to squeeze out additional performance gains.
Use Divi's built-in lazy loading — in Divi > Theme Options > Performance, enable Lazy Loading for images. This defers loading of images below the fold until the user scrolls down, which directly improves your LCP score.
Set explicit image dimensions — when adding images to Divi modules, always specify the width and height. This prevents layout shift (CLS) by telling the browser how much space to reserve before the image loads.
Avoid using giant images as section backgrounds — Divi allows you to set any image as a section background. These load even on mobile at full desktop resolution unless you have set specific responsive sizes. Keep section background images under 200KB after compression.
Use the correct image size per module — Divi's Image module, Blog module, and Portfolio module each use different image sizes. Using an image that is far larger than the module displays wastes bandwidth. In most cases 1200 pixels wide is sufficient for the main content area.
Step 7 — Re-test and Verify
After completing these steps, run your PageSpeed Insights test again. On most Divi sites following this process produces:
- LCP improvement of 1 to 3 seconds
- PageSpeed mobile score increase of 15 to 35 points
- Page weight reduction of 60 to 80 percent
Keep in mind that PageSpeed scores fluctuate slightly between tests — run the test three times and take the average rather than relying on a single result.
How Much Difference Does This Really Make?
To put some numbers on it: the average web page contains around 1,900KB of images according to the HTTP Archive. After compression and WebP conversion the same images typically weigh between 400 and 700KB. On a 4G mobile connection that difference translates to approximately 1.5 to 2.5 seconds of load time.
For e-commerce sites running on Divi, that improvement has a direct revenue impact. Research by Deloitte found that a 0.1 second improvement in mobile site speed increases conversion rates by 8 percent for retail sites.
Summary
Speeding up a Divi website with image optimisation comes down to four things: compress images on upload, convert to WebP, limit maximum image dimensions, and use lazy loading. Done correctly these changes require almost no ongoing effort — you set them up once and they run automatically on every upload.
Divi Image Compressor handles the compression and WebP conversion automatically, with no API key, no subscription, and full compatibility with Divi 4 and Divi 5. It is available as a yearly subscription on the Elegant Themes Divi Marketplace.
Frequently Asked Questions
Will compressing my images affect their visual quality?
At 80% quality (the default setting) the difference is not visible to the human eye at normal screen sizes. The compression algorithm removes data that your eye cannot perceive. If you are selling fine art photography you may want to use 90%, but for standard business or portfolio sites 80% is the right balance.
What is WebP and is it safe to use?
WebP is an image format developed by Google and is now supported by all major browsers including Chrome, Safari, Firefox, and Edge. It is completely safe to use and is actively recommended by Google for web performance.
Will this work with Divi 5?
Yes. Divi Image Compressor is fully compatible with Divi 4 and Divi 5 including the Visual Builder. It hooks into WordPress's core upload pipeline which both versions of Divi use.
What happens if my server does not have GD Library or ImageMagick?
The plugin's status banner will alert you if neither is available. In practice virtually all shared hosting environments include at least GD Library by default. If neither is available contact your hosting provider — it is a standard PHP extension that can be enabled in minutes.
Get Divi Image Compressor
Divi Image Compressor is available as a one-time purchase on the Elegant Themes Divi Marketplace. There are no subscriptions, no API keys, and no limits on how many images you can compress.
Divi Image Compressor is developed by DiviPerfect — a suite of Divi 5 plugins built for freelancers, agencies, and businesses. Questions? Email us at hello@diviperfect.com or visit diviperfect.com.