Uppercase vs Lowercase: When to Use Each

Capitalization rules confuse even experienced writers. Here's the practical guide — plus a one-click way to fix any text.

UPPERCASE: use sparingly

All-caps reads as shouting online and hurts readability. Reserve it for short warnings, abbreviations (NASA, HTML), and occasional design accents — never full paragraphs.

lowercase: the default

Body text, emails, and descriptions live in lowercase (with normal sentence capitalization). URLs and email addresses are effectively lowercase — slugs should always be.

Title Case: headings and titles

Capitalize major words in article titles, book names, and headings. Most style guides lowercase short words (a, the, and, of) unless they're first.

Sentence case: the modern default

Capitalize only the first word and proper nouns. Google, Apple, and most modern brands use sentence case for headings and buttons — it's calmer and easier to scan.

Fix any text in one click

Pasted a paragraph in the wrong case? Run it through our free case converter to switch between UPPER, lower, Title, and Sentence case instantly.