PDFs that look wrong on everyone else's computer
5 min read
“The file you sent looks broken” is rarely file corruption. It's almost always fonts — and once you know the mechanism, prevention is easy.
PDF can carry its fonts inside the file
The reason PDF “looks the same everywhere” is that the fonts used in the document can be stored inside the file itself. This is called font embedding.
When the program that produced the PDF skips embedding, the file only carries an instruction — “draw this text in such-and-such font”. If the reader's computer doesn't have that font, another one is substituted, or in the worst case the characters render as boxes (□).
Why some scripts are hit harder than others
A Latin font needs only a few hundred glyphs, but fonts for Korean, Japanese, or Chinese carry thousands to tens of thousands, making them large. Some programs default to skipping embedding for these fonts to keep files small — which is exactly how broken documents get made.
Documents set in a company's licensed commercial font are the riskiest: the only computers with that font installed are inside the company. The more external the audience, the more the embedding check matters.
How to check before sending
The reliable check is the document's font list. In the PDF Info tool or your viewer's document properties, confirm every font is marked “Embedded”. Any font without that mark can break on the recipient's machine.
There's also a quick practical test: open the file on your phone or a different computer. A PDF without embedded fonts reveals itself immediately outside the machine that created it.
Settings that prevent it at creation time
In Word, choosing “ISO 19005-1 (PDF/A) compliant” in the PDF export options forces fonts to be embedded. Most other programs have an “Embed fonts” option somewhere in their PDF settings — the rule is simply to find it and turn it on.
Occasionally a font's license forbids embedding, and the program warns you. The cleanest fix is swapping just that font for a freely embeddable one.
If you received a broken file
If the fonts are broken on your side, there is realistically nothing you can do to repair it — the font data simply isn't in the file. The proper fix is asking the sender to export again with fonts embedded.
If you only need to read the content urgently, ask the sender for an image-converted copy of the pages instead. Images look identical everywhere regardless of fonts — at the cost of text search and copying.