Image Optimization Guide

Choose the format by use case

JPEG is usually the first candidate for photos, WebP is a strong default when browser support is acceptable and you want better compression, PNG still matters for transparency or crisp UI exports, and Base64 image data only makes sense for very small assets or constrained embedding cases.

The hidden cost of oversized assets

Large dimensions hurt even when file size looks reasonable, because the browser still has to decode and rasterize the pixels. Teams often compress but forget to resize, or generate a WebP file that is still far larger than the layout requires. Good optimization therefore checks both bytes and rendered dimensions.

• Resize before compression if the displayed box is much smaller than the source.
• Compare visual quality at the exact layout size, not only at 100% zoom.
• Avoid inline Base64 for large images because payload growth hurts transfer and caching.

A practical optimization loop

Start with the original file, resize to the maximum layout need, compress into the likely output format, then compare the result visually and numerically. If the asset is for a hero section, test the mobile viewport too. If it is for documentation or a UI guide, prioritize legibility over raw compression ratio.