One common statement from the WAP advocates (who, like the World War I veterans, are getting fewer by the year) is that WML is a more compact language than (X)HTML. Not so. It is a simpler language, you don’t need an as advanced browser to handle it, but the WML source is actually more bloated than HTML precisely because it is a simpler language. Since WML 1 doesn’t even have the headline elements (‘h1’ to ‘h6’), you can’t use code like <h2>A subhead</h2>, you have to do something like <big><big><b>A subhead</b></big></big>. Not only do you lose the useful information that “A subhead” is a headline, you need more markup to say less.
There are some byte optimisations, WML align=”c” is shorter than align=”center”, though using CSS would be even shorter than either of the two. HTML has some inefficient quirks, ‘strong’ and ‘b’ are used for the same purpose, and ‘s’ and ‘strike’ are two elements for the same visual effect. Sometimes old-style WML too use more verbose syntax, like <anchor>link text<go href=”url”></anchor> for <a href=”url”>link text</a>. More usefully WML has a compressed non-XML format confusingly called “binary XML” that gives considerable savings when the page is sent uncompressed from server to client. When sent compressed the gains would be minor.
The WAP graphics format WBMP is the only uncompressed format you will find on the web. Again designing for simplest possible processor doesn’t make for a compact format. The saving grace is that only black and white are allowed, WBMP images are supposed to be tiny, and that it doesn’t matter much if the data stream is compressed anyway.
Now, in the real world a WML page may be a few KB, while the source code for a news site like cnn.com might run into over a hundred, with the graphics clocking in hundreds more. Surely the WML page gives more news for the byte. Yes, it does, but that is not due to WML being a more compact format, but due to the WML page being crafted for small size. An equivalent HTML page will always be smaller, and an HTML+CSS page smaller still.