When to capitalize a sentence

The first word of every sentence is always capitalized in standard English. Proper nouns — names of people, places, organizations, and products — are also capitalized regardless of where they appear.

Titles and headings follow separate capitalization rules depending on the style guide. The four modes above cover the most common capitalization formats used in publishing, digital content, and formal writing.

Sentence case vs title case

Sentence case capitalizes only the first word and proper nouns, making it the dominant format for British English publications, software interfaces, and most digital products. It reads as natural and conversational.

Title case capitalizes every major word and is the American standard for book titles, newspaper headlines, and formal headings. The specific rules about which words to lowercase vary by style guide.

Using all caps and lowercase

All caps converts every letter to uppercase and is best reserved for short phrases that need maximum emphasis, such as warnings, alerts, and design headlines. Extended all-caps text is harder to read than mixed case.

Lowercase removes all capitalization and is required for URL slugs, code identifiers, and file names. It also appears as a deliberate stylistic choice in branding, social media, and creative writing.

Need title case for a specific style guide?

The main converter on this site supports 12 style guides, including AP Style, Chicago Style, MLA Style, APA Style, and more. Each style guide has different rules about which words to capitalize.