Title case converter

Why a title case converter needs three modes

Every English style guide starts from the same instinct: capitalize the important words, leave the connective tissue alone. They disagree about where the tissue ends. The Associated Press wrote its rule for wire copy set in narrow columns, and it drew the line by length — conjunctions, prepositions and articles of three letters or fewer stay lowercase, everything else is capitalized. The Chicago Manual of Style wrote its rule for books, and drew the line by part of speech — a preposition is a preposition whether it has two letters or ten, so it stays lowercase either way. MLA writes for scholarly citation, where the same title has to be recognizable across a bibliography, and follows Chicago closely with a few words reclassified.

Neither rule is more correct than the other. They optimize for different things: AP for a headline that has to survive being scanned in a second, Chicago for a title page that has to look composed. The practical consequence is that the same sentence comes out three different ways, and a tool that offers a single "title case" button is quietly picking one for you without saying which.

Where AP and Chicago actually split

The divergence is almost entirely about prepositions of four letters or more. Take walking through the fire with grace from here:

• AP: Walking Through the Fire With Grace From Here
• Chicago: Walking through the Fire with Grace from Here

Three words, three disagreements, in one short headline. The same happens with between, about, under, against, during, toward and without — all capitalized by AP, all lowercase in Chicago. Short prepositions like of, in, on and to are lowercase in both, which is why so many people never notice the guides differ at all: the difference only appears once a headline reaches for a longer word.

Chicago and MLA are much closer, and the clean split between them is the word as. Chicago names it explicitly as a word to lowercase. MLA treats it as a conjunction rather than a preposition, so it gets capitalized: Strong as an Ox in Chicago becomes Strong As an Ox in MLA. Switch between the two modes above on a title containing as and that single word is the only thing that moves.

The rule that overrides everything

All three guides capitalize the first and last word of a title no matter what the word is. Of Mice and Men keeps its capital O; What Are You Waiting For keeps its capital F. This tool applies the same override after a colon, because the subtitle is treated as its own unit — The Art of War: A Study of Strategy, not a study.

Hyphenated compounds follow the same lowercase lists inside the compound, which is how mother-in-law becomes Mother-in-Law rather than Mother-In-Law. The second element is capitalized when it is a real word and left alone when it is one of the small connective ones.

Why Swedish capitalizes only the first word

Title case is not a universal typographic convention. It is an English-language habit, and Swedish never adopted it. Swedish orthography capitalizes the first word of a heading, proper nouns, and nothing else. The converter leaves capitals you already wrote in place because it cannot know whether Paris, Monday or Du is a name in your context. Check those words when the source arrived in English-style title case; removing a real proper noun's capital would lose information the result cannot recover.

There is a second difference the Swedish mode handles. In English, the first word of a subtitle after a colon is capitalized. In Swedish it is not, unless what follows is a complete sentence or a quotation. So Guide till rubriker: så gör du keeps its lowercase så, while the English sentence-case mode capitalizes the same position. That is the entire difference between the two modes, and it is why they are separate buttons rather than one.

Pasted headlines, and what this cannot see

Headlines usually arrive in capitals, because that is how they sat in the design they were copied from. A line with no lowercase letters at all is left exactly as written by default, because the capitals may be deliberate: HTML AND CSS should survive intact, and no tool can tell an acronym from a shouted word. The receipt says when a line was kept that way. Tick Rewrite lines typed in ALL CAPS to have such a line rewritten from scratch — then read the acronyms, because they come back as ordinary words. Lines are handled one at a time, which pairs well with removing the line breaks a PDF left behind first, and with running the finished headline through the slug generator afterwards.

What no lowercase list can resolve is grammar. In Turn on the Lights, on is a particle belonging to the verb, and every style guide capitalizes it — but it is spelled exactly like the preposition in A House on the Hill, and this tool lowercases both. The same applies to up, out and off in phrasal verbs. Those are the cases worth a second look before you publish; everything else the style lists get right.