When to Use UPPERCASE in Writing (Hint: Rarely)
All-caps text reads ~13% slower than mixed case because every letter has the same height — we lose the word-shape cues our eyes rely on. Keep it for short labels, acronyms, and deliberate emphasis.
Good uses
- Short button labels (SUBMIT, CANCEL)
- Warning and error states
- Section headers under 4 words
- Acronyms and initialisms (NASA, HTML)
Bad uses
- Body paragraphs
- Long headlines
- Accessible content (screen readers often read each letter)