A short history
PNG (Portable Network Graphics) was created in 1996 as a free, patent-unencumbered replacement for GIF, after the company holding the patent on GIF’s LZW compression began demanding licensing fees. The community designed PNG in the open to be better in almost every way — more colours, better compression, and true transparency — while staying completely royalty-free.
How it works
PNG is lossless: it stores every pixel exactly, compressed with the DEFLATE algorithm (the same one used in ZIP). Its standout feature is a full 8-bit alpha channel, so each pixel can be anywhere from fully opaque to fully transparent — giving soft, anti-aliased edges over any background. That precision is why PNG files are large for photographs but ideal for graphics.
When & how to use it
Use PNG for anything with hard edges or transparency: logos, icons, UI elements, screenshots, and diagrams. It keeps text and lines razor-sharp where JPEG would smear them. For photographs, prefer JPEG, WebP or AVIF — a photo saved as PNG is lossless but often several times larger for no visible benefit.
- Released in 1996 as a royalty-free replacement for GIF.
- Lossless DEFLATE compression — identical to the source, every time.
- Full 8-bit alpha channel for smooth, anti-aliased transparency.
- The name is a recursive joke: “PNG’s Not GIF”.