Generate PDFs
from Ruby

Install the Ruby gem

Add the package to your application:

bundle add ironpress

Or install it globally:

gem install ironpress

Releases include native gems for supported Linux, macOS, and Windows targets, plus a source gem.

Create an HTML PDF

The module function returns a binary Ruby String containing the complete PDF:

require "ironpress"

html = <<~HTML
  <style>
    @page { size: A4; margin: 18mm; }
    h1 { color: #295dff; }
  </style>
  <h1>Hello from Ruby</h1>
HTML

pdf = Ironpress.html_to_pdf(html)
File.binwrite("output.pdf", pdf)

Render Markdown

pdf = Ironpress.markdown_to_pdf(
  "# Release notes\n\nEverything shipped."
)
File.binwrite("release-notes.pdf", pdf)

Build a reusable policy

Each configuration call returns a new converter value, so settings compose naturally in a chain:

converter = Ironpress::HtmlConverter.new
  .page_size("Letter")
  .margin_sides(36, 48, 36, 48)
  .header("Quarterly report")
  .footer("Page {page} of {pages}")

pdf = converter.convert("<h1>Results</h1>")
markdown_pdf = converter.convert_markdown("# Results")

Use convert_to_file or convert_markdown_to_file for direct file output.

Load local resources and fonts

Grant a resource boundary, then pass custom font data as a binary string:

converter = Ironpress::HtmlConverter.new
  .base_path("templates")
  .resource_root(".")
  .add_font("Inter", File.binread("assets/Inter.ttf"))

pdf = converter.convert(<<~HTML)
  <style>body { font-family: Inter }</style>
  <img src="assets/logo.png">
HTML

Optional CJK and emoji font packs also enter as caller-provided bytes. The renderer never downloads them.

Handle failures and runtime limits

Invalid named settings raise ArgumentError. Conversion failures raise RuntimeError, while file operations keep Ruby's normal I/O errors.

• HTML sanitization is enabled by default.
• The Ruby binding has no async or streaming conversion API.
• Remote HTTP document resources are not available from the gem.
• Use a browser renderer for JavaScript-driven pages or exact Chrome output.

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