Text Case Converter: When to Use Uppercase, Lowercase, Title Case

Text case isn't just aesthetics — it's part of language rules, publishing standards, and programming conventions. Here's when to use each case and the rules that govern them.

Sentence Case

Capitalize only the first word of a sentence and proper nouns. This is standard for body text in English — the way you write paragraphs. Also used for most UI labels, buttons, and form field labels in modern design systems.

Title Case

Capitalize the first letter of major words. Rules vary by style guide:

• AP Style: Capitalize all words 4+ letters. Capitalize verbs and adjectives of any length.
• Chicago Style: Same as AP but more consistent — capitalize all significant words.
• APA Style: Used in academic writing; capitalize all words 4+ letters in titles.
• Always lowercase (regardless of style): a, an, the, and, but, or, for, nor, at, by, for, from, in, into, of, off, on, onto, out, over, to, up, with

ALL CAPS

All uppercase letters. Used for: acronyms (GST, CEO, API), legal text emphasis, warning labels, and decorative headings. Avoid for long text — it's harder to read and can come across as shouting.

Programming Cases

• camelCase: First word lowercase, subsequent words capitalized (myVariableName). JavaScript standard for variables and functions.
• PascalCase: All words capitalized (MyClassName). Used for class names in most languages.
• snake_case: Words separated by underscores, all lowercase (my_variable_name). Python, Ruby, SQL standard.
• kebab-case: Words separated by hyphens, all lowercase (my-css-class). CSS classes, URL slugs.
• SCREAMING_SNAKE_CASE: All uppercase with underscores (MAX_VALUE). Constants in many languages.

Convert any text to any case with our Text Case Converter.