What is PNG? | GenClean Glossary

PNG

PNG (Portable Network Graphics) is a lossless image format: every pixel is preserved exactly, and it supports full transparency. That makes it the right choice for screenshots, logos, diagrams, and UI graphics - and the wrong choice for photographs, where its exactness produces files many times larger than an equivalent JPG.

Why PNGs of photos are huge

PNG's compression works by finding repeating patterns. Graphics with flat colors repeat constantly and compress beautifully; photographs are full of sensor noise that never repeats, so PNG stores nearly all of it literally. A photo saved as PNG is commonly 5-10x the size of a visually identical JPG.

Transparency

PNG carries an alpha channel with 256 levels of opacity per pixel, which is why logos and cutout product shots ship as PNG. If a design needs transparency and small size together, WebP covers both.