What is PNG?
PNG (Portable Network Graphics) is a lossless raster image format that supports full alpha transparency and up to 16-bit color depth per channel. Because compression is lossless, PNG is the right choice for screenshots, logos, and graphics with sharp edges or text — but it produces larger files than JPEG for photographs.
Example
A screenshot with transparent corners should be saved as PNG, not JPEG.
Related tool
Try it on ToolSphere — runs entirely in your browser, nothing is uploaded to a server.