The most popular JavaScript PDF library — jsPDF is a browser-first MIT-licensed library (~30k+ GitHub stars) for generating PDFs directly client-side in the browser with no server round-trip: text, images, shapes, form fields, and HTML-to-PDF via plugins (html2canvas, autotable, svg). Works in Node.js too, but the browser is its sweet spot. A rich plugin ecosystem extends it for tables, SVG, and HTML. No paid tier, no SaaS — the default pick for client-side PDF generation.