Like print ads, banner ads come in a variety of shapes and sizes. The Internet Advertising Bureau (IAB) specifies eight different banner sizes, according to pixel dimensions. A pixel is the smallest unit of color used to make up images on a computer or television screen. The IAB's standard banner sizes are:
- 486 x 60 Pixels (Full Banner)
- 392 x 72 Pixels (Full Banner with Vertical Navigation Bar)
- 234 x 60 Pixels (Half Banner)
- 120 x 240 Pixels (Vertical Banner)
- 125 x 125 Pixels (Square Button)
- 120 x 90 Pixels (Button 1)
- 120 x60 Pixels (Button 2)
- 88 x 31 Pixels (Micro Button)
The full banner (468 x 60) is by far the most popular, but you will see all these variations all over the Web. These are not the only banner ad shapes and sizes, either, but they are a good representation of the range of common banner ads. There is no universal file-size constraint for banner ads, but most Web sites impose their own limits on memory size, usually something like 12K to 16K. This is because banner ads add to the total file size of the page they appear on, therefore increasing the time it takes for a browser to load that page.
As you've probably noticed while surfing the Web, actual graphic content, or creative, varies considerably among banner ads. The simplest banner ads feature only one, static GIF or JPEG image, which is linked to the advertiser's home page. More common is the GIF-animated banner ad, which displays several different images in succession, sometimes to create the effect of animated motion. Then there are rich media banner ads -- ads that use audio, video, or Java and Shockwave programming. These banner ads, which usually have larger file sizes, are often interactive beyond their simple linking function.