I developed a public API to build PDF files from web pages. It has a nice PHP client class that makes it super easy to use. It uses wkhtmltopdf to render the PDF in the cloud.
No need for anything special in the HTML. No need for absolute URLS in images/css/js links. Works on localhost (dev machine) too.
Currently the service has endpoints in 4 Azure regions: US East, US West, EU North, Southeast Asia.
It's fast since it uses a proprietary protocol to send the web page contents to the API for conversion to PDF.
It's reliable because all endpoints are load balanced.
Free account available for testing or low usage. Details on the web site:
https://rotativahq.com