How do I fix slow load times on my before and after gallery page

We covered why before-and-after galleries tend to cause speed issues in a dedicated post. This one is the practical remediation walkthrough: the specific steps to actually fix an existing, already-slow gallery page, rather than the general principles behind why it happens.

Step 1: Confirm the Gallery Page Is Actually the Problem

Before making changes, run your specific gallery page, not just your homepage, through PageSpeed Insights, as covered in our speed testing guide. Compare its score against your homepage’s score. If the gallery page scores meaningfully worse, that confirms the images on this specific page carry a distinct issue worth addressing directly.

Step 2: Identify Your Largest, Unoptimized Images

Within the PageSpeed Insights report, look at the “opportunities” section for image-related recommendations — it typically flags specific images and their current file sizes. Open your media library and sort or review your gallery images to identify the largest offenders. You’ll likely find a handful of particularly oversized files driving a disproportionate share of the problem.

Step 3: Re-Upload Oversized Images in Properly Compressed, Correctly Sized Versions

For each large image you identify, run it through a compression tool like TinyPNG or an automatic WordPress plugin, as covered in our image compression tools post, and resize it to match its actual display dimensions on the page rather than leaving it at full camera resolution. Replace the existing oversized version in your media library with this optimized version.

Step 4: Install or Configure Lazy Loading Specifically for This Page

As covered in our lazy loading explainer, confirm that images below the initial visible area on this specific gallery page load only as a visitor scrolls toward them. If your gallery plugin doesn’t support this natively, check whether a general WordPress lazy loading plugin or built-in WordPress feature covers it. Gallery pages, given how many images they typically contain, benefit disproportionately from this specific fix.

Step 5: Evaluate Your Current Slider or Comparison Format

If you’re using a before-and-after slider plugin, check whether it loads both the before and after images at full size simultaneously, as covered in our original before-and-after speed post. If the plugin doesn’t offer an optimization setting for this, consider whether a simpler side-by-side format might perform better for this specific page, particularly if you have many comparison pairs.

Step 6: Convert Images to a Modern Format if Not Already Done

As covered in our image compression tools post, check whether your optimization plugin supports WebP conversion, and confirm your gallery images actually use it. This format often delivers a meaningful additional file size reduction beyond basic compression alone.

Step 7: Re-Test the Page After Each Major Change

Rather than making every change at once and testing only at the end, re-run PageSpeed Insights after the image optimization step, then again after the lazy loading step. This lets you see which specific changes produced the most improvement — useful both for confirming your work and for understanding what to prioritize on other image-heavy pages.

Step 8: Set Up a Process to Prevent This From Recurring

As covered in our post on speed eroding as content gets added over time, fixing your current gallery solves only half the task. As covered in our image compression tools post, confirm your optimization plugin automatically compresses future uploads, which keeps new before-and-after results from reintroducing the same problem as you continue adding patient results over time.

A Quick Reference Checklist

• Confirmed the gallery page specifically scores worse than other pages
• Identified the largest, most unoptimized images
• Re-compressed and properly resized those images
• Confirmed lazy loading is active for below-the-fold gallery images
• Evaluated whether your slider format loads both images unnecessarily
• Confirmed modern image format (WebP) conversion is applied
• Re-tested after each change to confirm improvement
• Set up automatic optimization for future gallery additions

The Underlying Principle

A slow gallery page is rarely one single problem. It’s usually a combination of oversized images, missing lazy loading, and sometimes an inefficient slider format, each contributing its own share to the overall slowdown. Work through these specific, concrete fixes one at a time, re-test after each, and you turn a vague “my gallery is slow” concern into a resolved, measurably faster page, backed by a process that keeps it fast as you keep adding results.

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