Web Design in a Nutshell, 2nd Edition

Minimizing GIF File Sizes

When you are designing and producing graphics for the Web, it is of utmost importance to keep your file sizes as small as possible. The standard guideline for estimating download time over a modem is 1 second per kilobyte. Of course, actual download times will vary widely, but this gives you a ballpark number to use for comparisons.

There are a few simple strategies you can follow to minimize the size of your GIF files, described in the following sections.

Tools for Optimizing GIFs

There are several software tools available specifically for creating and optimizing graphics for the Web. One of the greatest benefits is that they offer previews of your optimization settings (even providing side-by-side comparisons), so you can make adjustments to the settings while keeping an eye on the resulting file size and overall image quality.

The big two are Adobe Photoshop/ImageReady and Macromedia Fireworks. Both offer very similar controls for file format, color depth, palette dithering, loss, and color palette editing. If you want to make professional-level web graphics, it is highly recommended you use one of these tools. The one you choose is up to your personal preference. Photoshop has the advantages of being the industry standard program for digital imaging and an interface that many designers are already familiar with. Fireworks provides an all-in-one package, impressive compression rates, and good integration with Dreamweaver, the industry-standard web ...