Is there any way to convert HTML5 code to HTML3 code instantly? Like an online convertor or something like this. I need this Tool for an important project and I was thinking that such a Tool should already exist. I searched already this on Web but I didn't found anything. Thank you
It's not clear what is meant by "convert".
An HTML-3 browser will silently ignore any tags it doesn't recognize, so in effect it is already converted.
If it means that the converted page will be displayed and behave exactly the same as it would using an HTML-5 browser, then that's clearly impossible. There are many HTML-5 concepts that simply don't exist in HTML-3.
(And as a matter of interest, why would anyone want such a thing?)