Why WebP Should Be the Default for WordPress Images

Chasing a solid Lighthouse score usually starts with image weight. Among common formats, WebP consistently delivers smaller files at the same, or better, perceived quality, which translates into faster loads, stronger Core Web Vitals, and a smoother UX.

A brief overview

• Smaller files than JPEG/PNG (often ~25–35% lighter) at similar visual quality.
• Better performance: improved LCP and less layout jank.
• Broad browser support with easy fallbacks in code
• WordPress-ready out of the box: srcset for responsiveness, lazy-loading for speed, and CDN delivery for scale.

Why WebP beats JPEG/PNG in practice

WebP typically shaves off a third of image payload compared to other image formats, while maintaining a similar quality. Smaller file size means quicker paint and less layout shifts. Which are commonly picked up in a Page Speed Insights test.

One format for most cases.

• Photography: WebP (lossy) typically outperforms JPEG.
• UI/graphics: WebP (lossless) can replace bulky PNGs.
• Transparency: Fully supported when needed for image cutouts

SVG are still #1 for logos and icons.

WordPress Compatibility

Since 5.8, WordPress adopted WebP support and now allows us to natively upload, crop WebP images. Before this time, we would need to write a code exception to allow wordpress to accept media uploads in this format. WebP support is growing for all the major browser types.

How To Get Started using WebP Images on Your Website

Take your current image that you want to convert to a WebP Image, and find an online Webp Image Converter. There are many different options to choose from, but they can slightly vary with quality and compression rates. We recommend using the one provided by COMPRESSORDIE. They provide a WebP conversion + compression all in one online tool.

Conversion Steps

1. Locate and Download: Find the image you wish to convert within your WordPress Media Library and download the original file to your computer.
2. Upload to Converter: Visit https://compress-or-die.com/ and upload the downloaded image to their online converter.
3. Download New WebP Image: Once the tool has finished compressing and converting the image, download the newly generated WebP image to your computer.
4. Upload to Website: Return to your WordPress website and upload the new WebP image to your Media Library.
5. Replace Original Image: Navigate to the custom field or featured image area where the original, non-WebP image was being used. Remove the old image and replace it with the newly uploaded WebP version.
6. Update Page: Crucially, don’t forget to update the page or post once you have completed the image replacement to ensure the changes are saved and reflected on your live website.

WebP truly hits the sweet spot, striking an optimal balance of quality, size, and compatibility. It seamlessly integrates into WordPress’s robust image pipeline, making it an ideal default choice for most imagery. While WebP should be your primary focus, remember to retain SVG for vector-based assets like logos and icons. As technology evolves, consider layering in AVIF when your technical stack fully supports it, further pushing the boundaries of image optimization. By adopting this strategic approach to image formats, both your users and Lighthouse scores will benefit immediately and significantly.