In Short
Use PNG when your image requires transparent backgrounds, contains crisp text typography, or displays sharp vector logos. Use JPG for natural photographs, complex scenery, and full-screen backgrounds where lossy compression achieves 80% smaller file sizes.
The Golden Rule of PNG vs JPG
If the image contains real-world colors, gradients, and natural scenery (people, landscapes, products), choose JPG (or WebP). If the image contains flat colors, geometric sharp lines, UI interface elements, or requires transparency, choose PNG.
Frequently Asked Questions
Can JPG have a transparent background?
No. The JPEG specification does not support alpha transparency channels. Any transparent areas will be filled with a solid color (typically white).