Why Aren't My PDF's Fonts Displaying Correctly?

When PDF text renders as empty boxes, a substitute typeface, or garbled characters, the cause is almost always the same underlying issue: the font isn't embedded in the file.

Why this happens at all

A PDF can either embed the actual font data inside the file, or just reference a font by name and assume the reader's device has it installed. When the font isn't embedded and the viewing device doesn't have that exact font, the reader has to substitute something else — sometimes gracefully, sometimes as visible boxes or missing glyphs, especially with less common typefaces, custom fonts, or non-Latin scripts.

It's usually a problem from the original export

This almost always traces back to whatever created the PDF in the first place. Many tools embed fonts automatically and you'll never notice the issue; older software, some LaTeX configurations, and certain "print to PDF" drivers don't embed by default and need it turned on explicitly in their export settings.

Sidestepping the problem entirely

If you're generating a new PDF from a document rather than troubleshooting an existing one, converting through Word to PDF or HTML to PDF renders each page as a fixed image of exactly how it looked when created — so there's no font file for a reader to substitute later. The trade-off is the same one any image-based PDF has: no selectable text, so it's the right call when appearance matters more than being able to copy the text out.

If you only have the broken PDF

There's no reliable way to "fix" fonts in a PDF that already has the wrong ones rendering — the original font data is either embedded or it isn't. If the file otherwise seems intact but is behaving oddly beyond just the fonts, Repair PDF is worth trying in case the issue is a broader structural one rather than purely a missing font.

FAQ

Why does the PDF look fine on my computer but wrong on someone else's? The font is likely installed on your device but not theirs — a sign it wasn't embedded in the file, and the fix has to happen at the source, not on either reader's end.

Does this affect PDFs made from scans? No — a scanned PDF is an image of a page, not real text, so there's no font to embed or substitute in the first place.

Will re-saving the PDF fix a missing-font issue? Only if you re-save from the original source document with font embedding turned on. Re-saving the already-broken PDF just copies the same missing reference forward.