pdflayer - Free, powerful HTML to PDF API supporting both URL and raw HTML conversion. Unlimited document size, lightning-fast and compatible PHP, Python, Ruby, etc.
Screenshot Machine - Screenshot machine is an online website capturing service. Creates a screenshot or thumbnail of any online web page in couple of seconds for free.
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
URL2PNG - Screenshots as a Service. Capture snapshots of any website, right in your app, quickly and reliably.
Tcpdf - TCPDF: Open Source PHP Class for generating PDF documents
ApiFlash - ApiFlash is a powerful serverless screenshot API built with Chromium and AWS Lambda. It can easily scale to millions of screenshots per day and has an ever growing number of satisfied big clients.