What is happening
A font only contains pictures for the characters its designer included. When your device is asked to draw a character that no installed font has, it draws a placeholder instead: a square, a diamond with a question mark, or nothing. Designers call the empty square tofu.
Which styles are most affected
- Newer or rarer characters, such as the filled squares and some tiny letters, are more likely to be missing.
- Older phones, older operating systems and some apps with their own limited fonts show boxes more often.
- The mathematical styles are included in the fonts of most recent devices, so bold, italic and script usually work.
What to try
- Switch to a different style. Bold, italic and script have the widest support.
- Update the device. Newer systems add fonts for more characters.
- Try another app or browser, since each draws text slightly differently.
- If you are sending it to someone, ask what they see, and send a screenshot if they cannot.
You cannot see what others see
Your screen may be fine while the recipient sees boxes. For anything that matters, send plain text as well.