Title Case Converter

The title-case rules this tool actually implements

Most case converters capitalize Every Single Word and call it title case. Real title case is a rule system, and editors notice when it is faked. This tool implements the AP-leaning version, and since you are trusting it with your headlines, here are the exact rules it applies:

• First and last words are always capitalized, whatever they are: “Something to Believe In.”
• 19 minor words stay lowercase — a, an, the, and, but, or, nor, for, as, at, by, in, of, on, per, to, up, via, vs — and only when they are shorter than four letters.
• Words of four or more letters are capitalized, including prepositions: With, From, Over, Under. This is the AP four-letter rule, and it is the one hand-cased headlines get wrong most often.
• The first word after a colon is capitalized, even a minor one: “Remote Work: A Field Guide.”
• Hyphenated compounds capitalize every part: Well-Known, Best-In-Class. Chicago style would lowercase minor words inside a compound (State-of-the-Art); this tool capitalizes all parts, the common AP headline treatment.
• Words that already contain a capital are left untouched — iPhone, GitHub, NASA, McDonald’s survive conversion. The flip side: acronyms typed in lowercase are not recognized, so seo becomes Seo. Type acronyms in caps.

Sentence case is the same discipline in reverse. The tool lowercases everything, then capitalizes the first letter of the text, the first letter after sentence-ending punctuation, and the pronoun I (including I’m, I’ve, I’ll, I’d). What no rule-based converter can know is proper nouns — “paris” stays lowercase because nothing in the string says it is a city. Reread sentence-cased text before publishing and restore names by hand.

A worked example

Take the sample line loaded in the tool: writing for the web: a field guide for busy editors. Title case produces “Writing for the Web: A Field Guide for Busy Editors” — and every capital in it is a rule firing. Writing is the first word, forced. Both instances of for are on the minor list and under four letters, so they stay down. Web is not a minor word, so it rises. The colon after it triggers the subtitle rule, which is why A — a minor word anywhere else — is capitalized. Editors is the last word, forced. If you can predict those five decisions, you can spot-check any converted headline in seconds, which is the real skill this tool should leave you with.

Title case or sentence case — decide by platform, then stay put

Neither convention ranks better in search, and no credible study shows one reliably winning clicks. The choice is about register: title case reads editorial and formal, sentence case reads conversational and modern. What actually damages a site is mixing them.

The developer casings

The last four modes are for identifiers, not prose. kebab-case is the convention for URLs, CSS classes, and web file names — if you are casing a URL, the slug generator adds stop-word removal and length limits on top. snake_case belongs to Python, Ruby, and SQL columns. camelCase is JavaScript variables and JSON keys; PascalCase is classes and React components. The converter also splits existing camelCase boundaries when tokenizing, so myAPIKey converts to my-api-key, not myapikey.

Multi-line input converts line by line, so a pasted list of 30 headlines — or 30 variable names — converts in one pass and copies in one click.

Common mistakes

• Capitalizing Every Word Including Of and The — the most visible tell of a hand-cased headline.
• Lowercasing four-letter prepositions (with, from, over) in title case; AP capitalizes them.
• Forgetting the capital after a colon, where subtitles start.
• ALL CAPS for emphasis in headlines — it reads as shouting, and screen readers can spell unfamiliar capitalized words letter by letter.
• Trusting any converter with proper nouns in sentence case, or feeding it lowercase acronyms and shipping Seo.

Honest limitations

This is a rule-based converter with an English minor-word list; other languages get the four-letter rule without the list’s judgment. It follows one style — AP leaning — with no Chicago or MLA switch, so hyphenated compounds capitalize every part and some Chicago-trained editors will want State-of-the-Art instead. Sentence case flattens proper nouns and acronyms, and title case preserves existing capitals rather than knowing which words deserve them. It converts instantly and consistently; the five percent of judgment calls that make house style a craft are still yours.