PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Kernel for Image to PDF - Image to PDF Converter tool can convert BMP, JPG, JPEG, JPE, JFIF, TIFF, PNG, and ICO images to PDF documents.
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
JPEG to PDF - JPEG to PDF is a free program that can convert image files to PDFs.
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.
Convert-JPG-to-PDF.net - Convert JPG to PDF for free with this online service.