Opacity

This attribute can be used to great effect to deliver stunning visual effects in web browsers. It also turns out to be very useful in styling HTML controls such as file uploaders and comboboxes which in their default display format leave a great deal to be desired on the aesthetic front.

We have discussed opacity at great length elsewhere on this site. For Firefox and Opera this attribute should be specified in the form opacity:n where n is a value in the range 0..1. IE on the other hand requires the code filter:alpha(opacity=nn) where nn lies in the range 0..100. A fully opaque element has an opacity setting of 1 in Firefox/Opera and 100 in IE.

All three browsers discussed here allow opacity settings to be adjusted for a wide range of HTML elements including divisions, forms, paragraphs and spans. Indeed, opacity settings can even be changed for the body element.

This is an inherited property - i.e. in a child element, if not assigned, it takes the corresponding value from the containing parent.