How to Convert Webpages to PDF with an API: Invoices, Reports & More

Generating PDFs from HTML is one of the most common automation needs in business applications. Instead of wrestling with PDF libraries and their rendering quirks, you can use a screenshot API with PDF output to convert any HTML page into a clean, printable document.

Why HTML-to-PDF via API?

Traditional PDF generation approaches have serious drawbacks:

• wkhtmltopdf — Outdated rendering engine, poor CSS support
• PDFKit / jsPDF — Imperative API, can't render complex layouts
• Headless Chrome locally — Heavy, fragile, hard to scale

A screenshot API with PDF format support gives you:

• Modern CSS and JavaScript rendering
• Pixel-perfect output that matches your browser preview
• No local dependencies or binary installations
• Scalable from 1 to 100,000 PDFs per month

Example: Generating an Invoice PDF

Step 1: Build Your Invoice as HTML

Design your invoice using standard HTML and CSS. Use print-friendly styles:

<style>
  @page { size: A4; margin: 20mm; }
  body { font-family: 'Inter', sans-serif; color: #1e293b; }
  .invoice-header { display: flex; justify-content: space-between; margin-bottom: 40px; }
  .line-items { width: 100%; border-collapse: collapse; }
  .line-items th, .line-items td { padding: 10px; border-bottom: 1px solid #e2e8f0; }
</style>

Step 2: Host the Invoice Template

app.get('/invoice/:id', async (req, res) => {
  const invoice = await db.getInvoice(req.params.id);
  res.send(renderInvoiceHtml(invoice));
});

Step 3: Generate the PDF

const pdfResponse = await fetch(
  `https://pxshot.dev/api/capture?url=${encodeURIComponent(invoiceUrl)}&format=pdf&key=YOUR_KEY`
);
const pdfBuffer = await pdfResponse.arrayBuffer();

Other Use Cases

• Receipts — Email PDF receipts after purchase
• Reports — Weekly analytics dashboards as PDFs
• Certificates — Course completion or event attendance certificates
• Contracts — Pre-filled agreement documents
• Tickets — Event tickets with QR codes

Tips for Better PDF Output

• Use @page CSS for paper size and margins
• Avoid viewport-dependent layouts — use fixed widths
• Test with window.print() in your browser first
• Use web fonts with @font-face for consistent typography

PxShot supports PDF output with a single parameter change. Read the docs or try it free.