HTML to PDF in Ruby

Updated July 2026 · HTTP client: Net::HTTP — standard library, zero gems

The shortest reliable path from HTML to PDF in Ruby is not a rendering library — it’s an HTTP call to a rendering API. Your app sends HTML, a managed Chromium engine renders it exactly as Chrome would, and a PDF comes back. No browser binaries in your deploy, no native dependencies, no page-break surprises.

Complete example (generate_pdf.rb)

Set NIPPYPDF_API_KEY in your environment, then this is the whole program:

# generate_pdf.rb — run with: ruby generate_pdf.rb
require "net/http"
require "json"

uri = URI("https://api.nippypdf.com/v1/pdf")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer #{ENV.fetch('NIPPYPDF_API_KEY')}"
req["Content-Type"] = "application/json"
req.body = {
  html: "<h1>Invoice #1042</h1><p>Total: $2,508.00</p>",
  format: "A4",
  margin: "20mm",
  print_background: true
}.to_json

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true, read_timeout: 30) do |http|
  http.request(req)
end

raise "NippyPDF error #{res.code}: #{res.body}" unless res.is_a?(Net::HTTPSuccess)

File.binwrite("invoice.pdf", res.body)
puts "Wrote invoice.pdf"

All request options

POST https://api.nippypdf.com/v1/pdf accepts JSON; the response body is the binary PDF. Options mirror Chromium’s print pipeline:

{
  "html": "<h1>…</h1>",              // or "url": "https://example.com/invoice/1042"
  "format": "A4",                     // "A4" | "Letter" | "Legal" | { "width": "210mm", "height": "297mm" }
  "margin": "20mm",                   // uniform, or { "top": "…", "right": "…", "bottom": "…", "left": "…" }
  "landscape": false,
  "scale": 1.0,                       // 0.1 – 2.0
  "print_background": true,
  "wait_until": "networkidle",        // "load" | "domcontentloaded" | "networkidle"
  "header_html": "<span></span>",     // running header (use sparingly)
  "footer_html": "<span class=\"pageNumber\"></span> / <span class=\"totalPages\"></span>"
}

For pagination control — keeping blocks together, repeating table headers, paper sizes — see the page-break CSS guide.

The self-hosted alternatives, honestly

• wicked_pdf / pdfkit (Ruby): both shell out to wkhtmltopdf — unmaintained since 2020, page-break roulette included. Read more →
• Grover / Ferrum: Chromium via Node or CDP — browser output, browser babysitting.

If those trade-offs are fine for your workload, they are honest choices. The API exists for teams who want Chrome’s output without operating Chrome.

FAQ

Try your own markup in the live in-browser demo, or jump to another language: Node.js, Python, PHP, C#, Go.