There are a lot of questions about
HTMLWorker on StackOverflow.
Many of these questions remain unanswered as
HTMLWorker has been abandoned in favor of XML Worker.
HTMLWorker was initially meant as a parser for a small selection of HTML tags.
People started using it as if it were a full-blown HTML to PDF converter and then complained because
HTMLWorker doesn't support CSS parsing. The
HTMLWorker code grew organically up until a point
where it was no longer maintainable.
We started another project, called XML Worker. It can be used to convert XHTML to PDF.
It's not an URL to PDF converter in the sense that it won't "print your web site to PDF".
In HTML, you can encounter content at the end of the file that needs to be added at the start of the document.
When this happens, one would expect that the start of the document is the first page.
That isn't possible with iText as iText flushes finished pages to the
OutputStream as soon as possible
and there is no way to return to a previous page to add the extra content.