A Practical Guide to Image Formats and Compression
JPG, PNG, WebP, SVG: what each one is actually for, and how to avoid the compression mistakes that slow sites down.
The wrong image format is a silent speed problem you can fix in seconds
It’s easy to just drag whatever file you have into an image slot and move on, but different formats exist for genuinely different jobs, and using the wrong one is a quiet source of both bloated file sizes and worse-looking results. Knowing the basics here takes five minutes and pays off on every single image you ever upload.
JPG: your default for photographs
JPG handles complex, continuous-tone images like photos efficiently, compressing them to a manageable size while keeping most of the visual detail intact. It’s not ideal for flat graphics with sharp edges or text, where it can introduce visible fuzziness, but for photography, it’s the reliable default.
PNG: for anything that needs transparency or crisp edges
Logos, icons, and any graphic that needs a transparent background belong in PNG, which preserves sharp edges and flat color much better than JPG does. The tradeoff is file size — PNGs are typically much larger than JPGs for the same image dimensions, so use them only where transparency or crispness genuinely matters.
WebP: usually the smarter modern choice
WebP generally produces smaller files than JPG or PNG at a comparable visual quality, and modern browsers support it broadly. Many platforms will convert your images automatically, but if you’re uploading assets manually and have the option, WebP is usually the better default over the older formats.
SVG: for anything that’s actually vector artwork
Logos, icons, and simple illustrations that were designed as vector shapes should stay as SVGs rather than being exported to a raster format. SVGs scale to any size with zero quality loss and are typically tiny in file size, which makes them the right call for exactly this kind of asset.
Never upload straight from your camera or phone
A modern camera or phone produces images far larger than any website needs to display them at. Resize to something close to your actual display dimensions and compress before uploading — a quick pass through a free compression tool is often enough to cut file size dramatically with no visible quality loss.
