Images are typically the largest contributors to page weight, especially on visually rich sites.
Converting images to modern formats like WebP or AVIF can reduce file sizes dramatically while
maintaining acceptable visual quality. WebP offers broad browser support and often achieves 25–35%
savings over JPEG or PNG. AVIF can compress even more efficiently, though support and encoding speed may
vary depending on your server’s GD capabilities. WP Lightning Load integrates with PHP’s GD extension to
convert images automatically on upload and can also process existing media in batches.
Beyond format conversion, you can set a quality level—typically 80–85 is a good starting point—and cap
maximum dimensions to avoid serving unnecessarily large images. Many themes request multiple sizes via
WordPress’s responsive image system. The plugin can optimize those derivative sizes as well, ensuring
that every viewport receives an efficient file. Stripping metadata (EXIF) saves additional bytes with no
visual downside for most websites. For safety, consider keeping originals or maintaining a backup until
you validate that quality and dimensions meet your standards across hero areas, galleries, and product
images.
When combined with lazy loading and appropriate caching, optimized images yield quick wins on LCP and
bandwidth usage, particularly for returning visitors and those on slower mobile networks. Always test
compression settings on representative images, including those with fine gradients, text overlays, and
skin tones, so you can balance aesthetics with performance confidently.