Summary

Choose the Correct Format

• GIF is best for drawings with large areas of flat color or simple patterns.
• You need GIF if you want a transparent color or animation.
• Don't overuse animation
• JPEG is best for photographic-quality images.
• Scanned images should almost always be saved as JPEG.
• You can adjust the quality at which JPEG saves a file to balance image quality vs. file size.
• When in doubt, save in both formats or at several different quality levels, and compare picture quality and file size.

When Writing your HTML

• Always use the alt= attribute to provide alternate text.
• Alternate text should explain what the person can't see in the image.
• Provide width= and height= attributes to make a page appear to load more quickly.
• The best case is to have the width and height you specify match the image's dimensions exactly.
• For images with a small file size, use the width= and height= attributes to scale the image to your heart's content.
• Never use the width= and height= attributes to make a “thumbnail” preview of a very large file. Instead, make a separate, smaller picture of the exact size that you desire.