# wkhtmltopdf > An open-source command-line tool to convert HTML documents or web pages into PDF files. > More information: . - Convert a HTML document into PDF: `wkhtmltopdf {{input.html}} {{output.pdf}}` - Specify the PDF page size (please see `PaperSize` of `QPrinter` for supported sizes): `wkhtmltopdf --page-size {{A4}} {{input.html}} {{output.pdf}}` - Set the PDF page margins: `wkhtmltopdf --margin-{{top|bottom|left|right}} {{10mm}} {{input.html}} {{output.pdf}}` - Set the PDF page orientation: `wkhtmltopdf --orientation {{Landscape|Portrait}} {{input.html}} {{output.pdf}}` - Generate a greyscale version of the PDF document: `wkhtmltopdf --grayscale {{input.html}} {{output.pdf}}`