Edit PDF in browser then export it...

Hello,

I am looking to transform PDFs into HTML. The final goal is to be able to add comments, images, highlight, underline, etc. Then export it to PDF again after editing. Directly in a browser.

Something like PDFTron but free.

What I've already tried:

• Embed the pdf with PDFJS and get the coordinates of clicks on the pdf to display the comment on a layer over the pdf (But it doesn't work if you have to scroll through the document and I do not know how to convert it to PDF again...).
• Use the PDF2HTML library. But I can only get the text and not the CSS.

Do you have any ideas? I am open to all possibilities!

Thank you for your help!