Diagram-JS might be a bit more popular than PDFCrowd. We know about 1 link to it since March 2021 and only 1 link to PDFCrowd. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
To follow on with this, I've used https://pdfcrowd.com/ too. Source: about 3 years ago
❔diagram-js - Seems nice, but I don't really like how demos look. Source: 10 months ago
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
GoJS - GoJS is a JavaScript library for building interactive diagrams on HTML web pages. Build apps with flowcharts, org charts, BPMN, UML, modeling, and other visual graph types.
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.
mxGraph - mxGraph is a fully client side JavaScript diagramming library - jgraph/mxgraph
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
jsPlumb - jsPlumb is an advanced, standards-compliant and easy to use JS library for building connectivity based applications, such as flowcharts, process flow diagrams, sequence diagrams, organisation charts, etc. More than just a diagram library.