Continuous-tone images look best saved as JPEG (medium or low is all you need) and also give you the smallest file size. If transparency is needed, save as GIF, using an Adaptive palette with the fewest number of colors. Compare the look and file size of the images that follow. Click the image to see who is behind those crazy glasses. Download the PDF file to learn how to save transparent GIF images. (947 KB / 6 pages)

Flat-color images (anti-aliased) do well without any dithering, so using Photoshop's Indexed Color mode (with an Adaptive palette and a Dither of None) and then saving as GIF will give you the best results with the smallest file size. The number of colors you need will depend on the image - try using the least number possible to get the smallest file. Download the PDF file to learn more about Indexed Color mode. (165 KB / 1 page)

Black-and-white images need very few colors, so saving them as a GIF with Photoshop's GIF89a Export Filter lets you select a low number of colors (six colors works well on an anti-aliased image), and preview the image to quickly see how the image will look. Download the PDF file to learn how to use the GIF Export Filter. (74 KB / 1 page) Also, download the latest GIF89a Export Filter(60 KB) for Macintosh, Windows, or Unix platforms.

Gradations look best with as many colors as possible, so JPEG Medium is the best option for gradations. (JPEG gives a much smaller file size than GIF with an adaptive palette.) Download the PDF file to learn how to save JPEG images for the Web. (558 KB / 1 page)

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