# What is a ToUnicode map?

Source: https://epublab.com/glossary/tounicode/ (updated 2026-11-03)

A ToUnicode map (CMap) is a table in a PDF font that says which Unicode character each glyph represents. Without it, a program can draw the text but may not know what the letters are.

## Why it matters when you convert a PDF to EPUB

When the map is missing or wrong, the PDF looks fine but its extracted text is gibberish, symbols or empty: copying and pasting from it shows the same problem. A converter cannot recover the right characters from such a font without OCR, so the EPUB inherits the problem.