Most online banner ad creators require you to specify the height and width of the desired banner in order to begin the customization process. You can typically choose from stock images or upload your own in addition to adding custom text and graphics to make the final banner.
Most online banner ad creation tools begin with an interface that prompts you to enter the length and width of the image in pixels. Determine the appropriate size by measuring the space available on your website in the space above the main site header. From here, follow the tool's instructions to choose from available templates or to create a new ad from scratch. Many templates contain sample text that includes color and style formatting, as well as some graphics such as call-to-action buttons.
Some tools allow you to upload custom images to use as the background of the banner ad or as one element in the design. These tools commonly include text edition features that allow you to click anywhere on the ad space and type in your own messages. These tools typically contain options to change the size, font and color to match your company brand or the theme of the ad. Once you place all the images, export the ad as an image to upload it to your site.