JPG vs PNG: Which Image Format Should You Use?
5 min read
JPG and PNG are the two most widely used image formats on the web, and they are optimized for opposite jobs. JPG is a lossy format built for photographs; PNG is a lossless format built for graphics, screenshots, and images that need transparency. Picking the right one saves file size without sacrificing quality.
The short answer
Use JPG for photographs and complex images with millions of colors. Use PNG for screenshots, logos, icons, text-heavy images, and anything that needs a transparent background.
How their compression differs
JPG uses lossy compression: it permanently discards color information the human eye is unlikely to miss. That makes photos dramatically smaller, but repeated saving degrades quality step by step, a problem known as generation loss.
PNG uses lossless compression (DEFLATE): every pixel is preserved exactly. That's why a PNG screenshot has razor-sharp text while a heavily compressed JPG screenshot shows fuzzy artifacts around letters.
Transparency
PNG supports a full alpha channel, so any pixel can be partially or fully transparent, essential for logos and overlays. JPG has no alpha channel at all; converting a transparent PNG to JPG composites it onto a solid background (usually white).
Quality and file size in practice
A 12-megapixel photo might be 4 MB as PNG but 1.5 MB as a quality-85 JPG, visually identical to most viewers. The reverse is true for a UI screenshot: the PNG is often smaller and much sharper than the JPG.
- Photos for the web → JPG (or WebP/AVIF if supported)
- Screenshots, diagrams, pixel art → PNG
- Logos with transparent backgrounds → PNG (or SVG if vector)
- Images you plan to edit repeatedly → PNG, to avoid generation loss