PNG‑24 is suitable for compressing continuous-tone images; however, it produces much larger files than JPEG format. The advantage of using PNG‑24 is that it can preserve up to 256 levels of transparency in an image.

Transparency and Matte

Determine how transparent pixels in the image are optimized. See Optimize transparency in GIF and PNG images.

Interlace

Displays a low-resolution version of the image in a browser while the full image file is downloading. Interlacing can make downloading time seem shorter and can assure viewers that downloading is in progress. However, interlacing also increases file size.