The answer to your question depends on how the information is stored in the HTML file. If, for example, you have the data in HTML tables, DBD::AnyData can read the HTML tabled as if they were a database tables and write the data out as CSV. It would take about four lines of code total to go from the HTML tables to CSV tables. If your data is not in HTML tables, what format is it in? Is it each on the separate line of an HTML list, or always preceeded by some word, etc. etc. You can use general tools like HTML::Parser but there are also more specific tools for more specific structures and we have no way of knowing which of those to recommend without more details of your context.