GUIDE · CASE

Choosing between sentence case and Title Case

Letter case is a formatting decision with real conventions behind it. Pick the wrong one and a heading looks casual where it should look formal, or pompous where it should read plainly. This guide covers what each style is for and what an automated converter can and cannot do.

The four styles and their jobs

• Sentence case — capitalize the first letter and proper nouns only. Used for body text, table cells, button labels and most sentences. Reads like ordinary writing.
• Title Case — capitalize most or all principal words. Used for book titles, article headlines, section headings and form titles. Scans well at a glance.
• UPPERCASE — used sparingly for short labels: badges, table headers, footers, emergency signage. In long text it reads as shouting.
• lowercase — intentional in some brands and informal contexts; also the safe intermediate when normalizing mixed input before applying another style.

Why Title Case is not fully automatic

English style guides disagree about which words to capitalize in a title. Most agree that articles, short prepositions and coordinating conjunctions stay lowercase — a, the, in, of, and — but "short" means different lengths in different guides, and the same word changes role: through is a preposition in "walking through the park" and an adverb in "follow through". A converter applies one consistent rule and cannot inspect meaning.

Names, acronyms and specialist terms add a second layer. Converting to Title Case does not invent capitalization for words that should always be lowercase (iPhone, van Gogh, unit symbols like kg), and lowercase conversion destroys capitalization that carries meaning (the acronym RAM becomes the animal ram). Neither error is a bug in the tool; it is the limit of formatting without context.

A practical workflow

1. Normalize first. Run lowercase over mixed input so every word starts from the same state.
2. Apply the target style. Sentence case for prose, Title Case for headings and titles.
3. Review names, acronyms and style words. Restore iPhone, re-capitalize acronyms, and check the short function words against the style you follow.
4. Keep one style per block. A list of headings reads better with consistent casing than with per-item choices.

Which to choose

If the text will be read as a sentence or a paragraph, use sentence case. If it is a heading, a title or a short label that people scan, use Title Case. If you are normalizing data before a later step, use lowercase as the intermediate. The fastest test: read it aloud the way it will be read — silently and fast, or carefully and word by word.