html-to-pdf

HTML to PDF Converter

Pixel-perfect HTML to PDF conversion using Puppeteer (Chrome headless). Provides excellent support for Hebrew, Arabic, and other RTL languages with automatic direction detection.

Why Puppeteer?

• Pixel-perfect rendering: Uses actual Chrome engine
• Full CSS3/HTML5 support: Flexbox, Grid, custom fonts, backgrounds
• JavaScript execution: Renders dynamic content
• Automatic RTL detection: Detects Hebrew/Arabic and sets direction
• Web font support: Loads custom fonts properly

Auto-Fit (Built-in, No Flag Needed)

The script automatically handles content overflow:

• Small overflow (up to ~18%) → auto-shrinks font size to fit the page
• Large content → flows cleanly across multiple pages with smart page-break rules (no cutting headers, table rows, or images in half)
• Fits perfectly → does nothing

This runs automatically on every PDF generation. No flags needed.

CRITICAL: Fit Content to Single Page

Backgrounds on html or body cause extra pages! Put backgrounds on a container element instead:

@page { size: A4; margin: 0; }

html, body {
  width: 210mm;
  height: 297mm;
  margin: 0;
  padding: 0;
  overflow: hidden;
  /* NO background here! */
}

.container {
  width: 100%;
  height: 100%;
  padding: 20mm;
  box-sizing: border-box;
  background: linear-gradient(...); /* Background goes HERE */
}

Common causes of extra pages:

1. Background on html/body - always put on .container instead
2. Content overflow - use overflow: hidden
3. Margins/padding pushing content out

Tips:

• Use --scale=0.75 --margin=0 if content still overflows
• For landscape: use --landscape

Setup (One-time)

Before first use, install dependencies:

cd ~/.claude/skills/html-to-pdf && npm install

Quick Usage

Convert local HTML file:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js input.html output.pdf

Convert URL to PDF:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js https://example.com page.pdf

Hebrew document with forced RTL:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js hebrew.html hebrew.pdf --rtl

Pipe HTML content:

echo "<h1>שלום עולם</h1>" | node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js - output.pdf --rtl

Options Reference

Option	Description	Default
--format=<format>	Page format: A4, Letter, Legal, A3, A5	A4
--landscape	Use landscape orientation	false
--margin=<value>	Set all margins (e.g., "20mm", "1in")	20mm
--margin-top=<value>	Top margin	20mm
--margin-right=<value>	Right margin	20mm
--margin-bottom=<value>	Bottom margin	20mm
--margin-left=<value>	Left margin	20mm
--scale=<number>	Scale factor 0.1-2.0	1
--background	Print background graphics	true
--no-background	Don't print backgrounds	-
--header=<html>	Header HTML template	-
--footer=<html>	Footer HTML template	-
--wait=<ms>	Wait time for fonts/JS	1000
--rtl	Force RTL direction	auto-detect
--expect-pages=<N>	Expected page count (warns if different)	1
--no-page-check	Disable page count warning	-

Automatic Overflow Detection

The script automatically checks page count after generating the PDF. By default, it expects 1 page and warns if the output has more:

⚠️  WARNING: PAGE OVERFLOW DETECTED!
   Expected: 1 page(s)
   Actual:   2 page(s)

   Fix: Reduce content, margins, or font sizes in HTML
   Use --no-page-check to disable this warning

Usage:

• Default: expects 1 page, warns on overflow
• --expect-pages=3: expects 3 pages (for multi-page documents)
• --no-page-check: disables the check entirely

Note: Requires pdfinfo to be installed (part of poppler-utils). If not available, the check is silently skipped.

Examples

Basic conversion:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js report.html report.pdf

Letter format with custom margins:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js doc.html doc.pdf --format=Letter --margin=1in

Hebrew invoice:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js invoice-he.html invoice.pdf --rtl

Landscape presentation:

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js slides.html slides.pdf --landscape --format=A4

No margins (full bleed):

node ~/.claude/skills/html-to-pdf/scripts/html-to-pdf.js poster.html poster.pdf --margin=0

Hebrew/RTL Best Practices

For best Hebrew rendering in your HTML:

1. Set lang attribute: <html lang="he" dir="rtl">
2. Use UTF-8: <meta charset="UTF-8">
3. CSS direction: Add direction: rtl; text-align: right; to body
4. Fonts: Use web fonts that support Hebrew (Noto Sans Hebrew, Heebo, Assistant)

Example Hebrew HTML structure (single-page):

<!DOCTYPE html>
<html lang="he" dir="rtl">
<head>
  <meta charset="UTF-8">
  <link href="https://fonts.googleapis.com/css2?family=Heebo:wght@400;700&display=swap" rel="stylesheet">
  <style>
    @page { size: A4; margin: 0; }
    html, body {
      width: 210mm;
      height: 297mm;
      margin: 0;
      padding: 0;
      overflow: hidden;
    }
    .container {
      width: 100%;
      height: 100%;
      padding: 20mm;
      box-sizing: border-box;
      font-family: 'Heebo', sans-serif;
      direction: rtl;
      text-align: right;
      background: #f5f5f5; /* Background on container, NOT body */
    }
  </style>
</head>
<body>
  <div class="container">
    <h1>שלום עולם</h1>
    <p>זהו מסמך בעברית</p>
  </div>
</body>
</html>

CRITICAL: Always Use scale=1.0 for Multi-Page PDFs

NEVER use --scale < 1.0 for multi-page documents. It causes:

• Content offset (not centered on page)
• RTL text overflow/clipping in grid layouts
• Unpredictable viewport width calculations

Instead: reduce CSS font sizes and spacing to fit content at scale=1.0.

.page {
  width: 210mm;         /* Matches A4 exactly at scale=1.0 */
  height: 297mm;        /* Matches A4 exactly at scale=1.0 */
  padding: 8mm 10mm 12mm;
  page-break-after: always;
  position: relative;
  background: #f7f8fa;
  overflow: hidden;
  box-sizing: border-box;
}

If content overflows at scale=1.0: reduce font sizes (10-11px base), padding, margins — NOT the scale. This keeps 1:1 mapping between CSS and PDF, eliminating all layout artifacts.

Color tip: Pure white (#fff) backgrounds wash out colored accents. Use #f7f8fa or #f8fafb for subtle contrast that makes colors pop.

Troubleshooting

Fonts not rendering correctly

• Add --wait=2000 for more font loading time
• Ensure fonts are loaded via @font-face or Google Fonts

Hebrew appearing left-to-right

• Use --rtl flag to force RTL direction
• Add dir="rtl" to your HTML element

Page breaks not working

Use CSS page-break properties:

.page-break { page-break-after: always; }
.no-break { page-break-inside: avoid; }

Backgrounds not showing

• Ensure --background is set (default is true)
• Use --no-background only if you want to exclude backgrounds

Auto-Fit Content (MANDATORY VERIFICATION)

CRITICAL - Claude MUST do this after EVERY PDF generation:

1. Read the PDF file using the Read tool to visually inspect it
2. Check for vertical overflow (empty pages, content spilling to next page)
3. Check for horizontal overflow (text cut off at sides)
4. If ANY issue found → FIX and regenerate (max 5 attempts)
5. Only deliver PDF to user after verification passes

This is NOT optional. Never deliver a PDF without visual verification.

Problems to Look For

Problem	Symptom	Fix
Vertical overflow	Empty space at page bottom, content on next page	Reduce --scale
Horizontal cut-off	Text cut at left/right edges	Reduce --margin AND fix HTML width
Both issues	Content cut AND extra pages	Fix HTML CSS first, then adjust scale

Fix Strategy (Max 5 Attempts)

Attempt 1: Default settings

node scripts/html-to-pdf.js input.html output.pdf

Attempt 2: If vertical overflow → reduce scale

node scripts/html-to-pdf.js input.html output.pdf --scale=0.9

Attempt 3: If horizontal cut-off → reduce margins

node scripts/html-to-pdf.js input.html output.pdf --scale=0.9 --margin=10mm

Attempt 4: If still issues → smaller scale + margins

node scripts/html-to-pdf.js input.html output.pdf --scale=0.8 --margin=5mm

Attempt 5: If still failing → FIX THE HTML CSS:

/* Add to HTML to prevent horizontal overflow */
.container {
  width: 100%;
  max-width: 100%;
  overflow-wrap: break-word;
  word-wrap: break-word;
  box-sizing: border-box;
}

STOP after 5 attempts - regenerate HTML with proper constraints.

HTML Width Fix (Required for Horizontal Fit)

If content is cut at sides, the HTML MUST have:

html, body {
  width: 210mm;  /* A4 width */
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.container {
  width: 100%;
  max-width: 100%;
  padding: 15mm;
  box-sizing: border-box;
  overflow-wrap: break-word;
}

Verification Checklist

After EVERY PDF generation, verify:

• All text visible (not cut at edges)
• No unnecessary empty pages
• Content fills pages properly
• No large gaps between sections

If ANY check fails → adjust and regenerate (max 5 times).

Technical Notes

• Uses Puppeteer with Chrome headless for rendering
• Waits for networkidle0 to ensure all resources load
• Automatically waits for document.fonts.ready
• Supports @page CSS rules for print styling
• Device scale factor set to 2 for crisp rendering