Troubleshooting
How to Fix Fonts Not Displaying Correctly in a PDF
Boxes instead of letters, substituted typefaces and shifted layouts all come from one cause: fonts that were not embedded.
A PDF can either carry its fonts inside it or simply name them and hope the reader has them. Almost every font problem you will ever see comes from the second case.
What you see when a font is missing
- Empty rectangles, or "tofu", where characters should be.
- A different typeface, usually a generic serif.
- Text spilling out of its box, or overlapping the text below.
- Correct letters but wrong spacing, because the substitute has different widths.
- Missing accented characters or symbols while plain text renders normally.
Check whether the fonts are embedded
- 1Open document properties in your reader.
- 2Find the Fonts tab.
- 3Look at each font. "Embedded" or "Embedded Subset" is what you want.
- 4Any font listed without that marker depends on the reader having it installed.
Fixing it
If you have the source document
Turn on font embedding and export again. In Word it is under Options → Save → Embed fonts in the file. Most design tools embed by default. This is the correct fix and the only one that reproduces the original exactly.
If you only have the PDF
Converting to PDF/A forces embedding of whatever the renderer can resolve, which stabilises the document — though if the original font is genuinely unavailable, a substitute gets embedded rather than the real thing. It stops the document changing from machine to machine, which is usually what you actually need.
If it is only on your machine
Install the font, or update your reader. If the document displays correctly for everyone else, the file is fine.
Why it matters more than it looks
Font substitution changes letter widths, which changes line wrapping, which changes page breaks. A contract that was ten pages when signed can be eleven pages on someone else's screen, with clauses on different pages. For anything where the pagination is referenced, embedding is not cosmetic.
Preventing it
- Always embed fonts when exporting.
- Prefer common families for documents that will be handled by many tools.
- Check the Fonts tab before distributing anything important.
- Use PDF/A for archival copies, where embedding is mandatory.
Do it now
PDF to PDF/A
Convert PDF to archival PDF/A format. It runs in this browser tab — your file is not uploaded anywhere.
Open PDF to PDF/AFrequently asked questions
Why do I see boxes instead of letters?+
The font is not embedded and your reader has no substitute containing those characters — common with non-Latin scripts.
Can I add fonts to an existing PDF?+
Not the original outlines. Re-export from the source, or convert to PDF/A to embed a substitute and stop the document shifting.
Does everyone see the same substitution?+
No. Each reader substitutes from what it has, which is why the document looks different everywhere.
Does embedding increase file size?+
Yes, though subsetting keeps only the characters used, which limits the cost considerably.