About PNG-8 format

The PNG-8 format uses 8-bit color. Like the GIF format, PNG-8 efficiently compresses solid areas of color while preserving sharp detail, such as the detail in line art, logos, or illustrations with type.

Because PNG-8 is not supported by all browsers, it may be advisable to avoid this format when your image must be accessible to the widest possible Web viewing audience. For more information about browser support for PNG, see your browser's documentation.

The PNG-8 format uses a lossless compression method, in which no data is discarded during compression. However, because PNG-8 files are 8-bit color, optimizing an original 24-bit image as a PNG-8 can degrade image quality. PNG-8 files use more advanced compression schemes than GIF, and can be 10%-30% smaller than GIF files of the same image, depending on the image's color patterns.

Note: With certain images, especially those with very few colors and very simple patterns, GIF compression may create a smaller file than PNG-8 compression. View optimized images in GIF and PNG-8 formats to compare file size.

As with the GIF format, you can reduce the number of colors in the image and choose options to control the way colors dither in the application or in the browser. The PNG-8 format supports background transparency and background matting, in which you blend the edges of the image with a Web page background color.