You create a document in Word using a specific set of fonts. You export it to PDF and send it to a colleague. They open the PDF and the fonts look wrong. The headings are in Arial instead of your custom brand font. The body text has shifted because a different font has different character widths. The document you designed and the document they see are visually different. The problem is font embedding, or more precisely, the lack of it.
Font embedding ensures that the fonts used in a document are included inside the PDF file itself. A PDF with embedded fonts displays correctly on any device, regardless of whether that device has the fonts installed. A PDF without embedded fonts relies on the reader's system to substitute missing fonts, and font substitution changes how the document looks. Embedding fonts during PDF conversion is a setting. Leaving it off is the default in many applications. The difference is a checkbox.
According to the PDF Association's technical documentation, font embedding is the single most common cause of cross-device PDF rendering differences. When fonts are not embedded, PDF readers substitute system fonts that may have different metrics, causing text to reflow, line breaks to shift, and the document to look different from the author's intention.
How Font Embedding Works
When a document is converted to PDF with font embedding enabled, the conversion software includes a copy of each font used in the document inside the PDF file. The embedding can be full, including every character in the font, or subset, including only the characters actually used in the document. Subset embedding produces smaller files while still ensuring correct display. Full embedding is larger but guarantees that any character can be added during later editing.
Some fonts have licensing restrictions that prohibit embedding. The conversion software will warn you if a font cannot be embedded and will either substitute a similar font or rasterize the text as an image. The PDF Fonts embedding status is visible in the PDF's document properties. Open the properties and check the Fonts tab. Every font should show as Embedded or Embedded Subset.
Enabling Font Embedding in Common Applications
In Microsoft Word, the PDF export options include a checkbox labeled Embed fonts in the file or Embed all characters. This option is in the Save As dialog under PDF options or in the Export settings depending on your Word version. Check this box before exporting. In Google Docs, font embedding is automatic for Google fonts and may not embed custom fonts added through the Extensions menu. Verify the output if you use custom fonts.
When converting a document to PDF using a browser-based tool, the Word to PDF conversion typically preserves the fonts from the source document if the conversion engine supports them. If fonts are missing in the output, convert the document using a different tool or export directly from the source application with embedding enabled.
Checking Font Embedding After Conversion
Open the PDF in any PDF reader and view the document properties. The Fonts tab lists every font used in the document and its embedding status. If any font shows as not embedded, the document will not display correctly on devices without that font. Fix the embedding at the source and reconvert. The verification takes seconds and prevents the embarrassment of sending a document that looks wrong to the recipient.
WukongPDF's PDF Format conversion tools preserve font information from the source document. After conversion, check the font embedding status in the output. Every font should be embedded. If any are not, adjust the source document settings and reconvert.
Troubleshooting Missing Fonts in the Output PDF
If fonts are missing after conversion, the source document may use fonts that do not permit embedding, or the conversion settings may not include font embedding. Check the source document for restricted fonts. Replace them with embeddable alternatives if necessary. If the conversion tool does not support font embedding, export from the source application with embedding enabled instead of using a browser-based converter.