Why is my HTML to PDF output missing fonts?

Fonts usually go missing in HTML-to-PDF output for one of these reasons:

1. The PDF engine can’t access the font files

   • The font is loaded from a path or URL the converter can’t reach.
   • Relative paths work in the browser but not in the PDF renderer.
   • The renderer may need an absolute file path or embedded base64 font.

2. The font is not embedded

   • Some tools don’t automatically embed fonts into the PDF.
   • If the viewer doesn’t have that font installed, it will fall back to another font or show blank/missing text.

3. CSS @font-face is incomplete or incorrect

   • Missing font-family, src, or correct format declarations.
   • Wrong file type for the converter, e.g. WOFF2 unsupported by some engines.
   • Example:

     @font-face {
       font-family: 'MyFont';
       src: url('/fonts/MyFont.ttf') format('truetype');
     }
     

4. The browser renders it, but the PDF tool uses a different engine

   • Chrome, wkhtmltopdf, Puppeteer, WeasyPrint, Prince, Playwright, etc. all have different font support.
   • A font that works in Chrome might fail in wkhtmltopdf or older headless browsers.

5. Web fonts are blocked or not fully loaded before PDF generation

   • If the PDF is generated before the font finishes downloading, fallback fonts are used.
   • In browser-based rendering, wait for fonts to load first:

     await document.fonts.ready;
     

6. Font licensing or subsetting issues

   • Some PDF generators subset fonts or fail with certain font encodings.
   • Rarely, the font itself may be corrupted or unsupported.

Things to check quickly

• Use absolute URLs for fonts.
• Make sure the font format is supported by your converter.
• Confirm the font is loaded before generating the PDF.
• Try embedding the font with @font-face.
• If using a tool like wkhtmltopdf, verify it supports the font format and CSS features you need.

If you want, I can help diagnose your specific setup if you share:

• the HTML/CSS font code,
• the PDF library/tool,
• and whether the font works in the browser but not in the PDF.