There are three ways you can significantly reduce the size of your animated GIF files:

• reducing the color palettes;
• reducing the number of cels (image layers);
• optimizing the individual image layers.

There are pros and cons to using the first two methods and they should be implemented judiciously. Keep in mind that the goal of creating animated GIF files is not to make them as compact as possible; creating compelling animations for the Web is.

However, until the time that data transmission speeds increase and everyone on the net has faster access, file size should still be a significant consideration when composing your animation.

The best way to reduce color palettes is to use the Global Palette as often as possible for displaying the colors of individual cels.

If one or more cels have slightly different colors included in their palettes, have your General Preferences set to accumulate new colors. This way you needn't create a Local Palette for a cel that varies only by a few colors from the rest.

If a cel has radically different colors from the others in the animation, your best bet is to give it a Local Palette and then reduce it by removing the colors it has in common with the Global Palette. Otherwise, the image may not display properly. The best reduced palettes are 16, 32, 64, and 128-color palettes.

The second method to reduce the file size of your animation is to delete any unnecessary cels. In some cases, this may not be desirable due to the adverse affects it may have on the quality of your animation. But if you can get away with cutting out a few cels here and there, such as the ones that don't alter the animation quality significantly, then you should do it.

Ulead GIF Animator allows you to greatly reduce the file sizes of the individual cels through a third method: Optimization.

When you select the File: Optimization Wizard command, GIF Animator analyzes the image layers in your animation, comparing them with one another, and then removes all the redundant pixels that each layer has in common. In some cases, this method can reduce your over all file size by as much as 200%.

Finally, you should consider cel sizes. If the motion of the animation occurs within a smaller field than the size of the "backdrop", or matte, then you shouldn't necessarily use cels that are the same size as your matte.

With GIF animations, you can easily overlap much smaller GIFs to create small areas of animation set against a static backdrop. Doing it this way will reduce your file size considerably, but again, only if the quality of your animation doesn't suffer as a result.