- Why does font embedding matter for printing?
- When a PDF is sent to a printer or a prepress RIP, the output device must have access to every font used in the document. If a font is not embedded, the RIP substitutes a fallback font — which almost always has different metrics, causing text to reflow, overflow text boxes, or render with incorrect characters. Professional print shops and PDF/X standards (PDF/X-1a, PDF/X-4) require all fonts to be embedded. A single missing font can cause a multi-thousand-dollar print run to be unusable.
- What is the difference between an embedded subset and a fully embedded font?
- An embedded subset contains only the specific glyphs (characters) that appear in the document, making the file smaller. You can spot it by a 6-letter prefix before the font name (e.g. "BCDKLM+Garamond"). A fully embedded font includes the entire character set, which is larger but required if the document will be edited after creation (e.g. a PDF form where users type new text). For read-only print output, subsets are perfectly fine and are what most professional layout applications produce by default.
- My PDF shows "Not Embedded" — how do I fix it?
- The fix depends on how the PDF was created. In Adobe InDesign or Illustrator, choose File → Export → Adobe PDF → Advanced, and ensure "Subset fonts when percent of characters used is less than" is checked. In Microsoft Word, go to File → Options → Save and enable "Embed fonts in the file". In Acrobat Pro, use Print Production → Preflight → "Embed missing fonts" fixup. After fixing, re-run this checker to confirm all fonts show PASS.
- Is my PDF file sent to a server when I use this tool?
- No. This tool runs entirely inside your web browser using the pdf.js library from Mozilla. Your file is read directly from your local disk by the browser's File API and is never transmitted over the network. You can even disconnect from the internet after the page loads and it will still work.
- What PDF font types does the checker detect?
- The checker identifies Type 1 (classic PostScript fonts), TrueType (TTF, common in Windows/Office documents), OpenType (OTF/CFF, the current standard for professional typography), CIDFont (used for CJK and large character set fonts), and Type 3 (custom glyph shapes defined in the PDF itself — always "embedded" by nature). The Standard 14 base fonts (Helvetica, Times-Roman, Courier, etc.) are flagged separately since viewers are required to supply them.