Using Exporters to Save Files
The majority of web browsers recognize GIF and JPEG images, so these two formats are used most often for saving web images. Newer browser versions also recognize the more recent PNG format, and many also support the Windows Wireless Bitmap (WBMP) and iMode formats, which are popular in wireless devices.
When saving files for the web, size is one of the most important factors which affects users trying to access your site. A larger file takes more time to download. You should use a file format that reduces the images size while keeping the quality as high as possible. The Export Wizards and Optimizers guide you through step-by-step, whereas the optimizers give you the most control.
To access any of the Optimizers you go through the File > Export > Exporter Choice. The example shown here is the first tab of the JPEG Optimizer. From here, you can manage compression amounts to reduce the size of your image. Remember, any time you compress an image; you are going to lose quality. The left image is the preview of your image before you apply any compression. The right side displays the way the image will appear once the compression is applied. In addition, just below the previews, the respective file sizes are displayed.