Title case capitalises the first word, the last word and every "important" word in a title, and leaves the small ones lowercase. What counts as small depends on the style guide, so there is no single title case: APA capitalises every word of four letters or more, while Chicago lowercases every preposition however long it is. The same headline can be correct in one style and an error in another.
Where do the style guides disagree?
Almost entirely on prepositions and conjunctions. Nouns, verbs, adjectives and adverbs are capitalised everywhere, and articles (a, an, the) are lowercase everywhere unless they open or close the title. The table shows where the rules part ways.
| Style | Lowercase in the middle | Capitalised |
|---|---|---|
| APA | Articles, and conjunctions and prepositions of three letters or fewer | Every word of four letters or more, including With, From and Between |
| Chicago | Articles, coordinating conjunctions, prepositions of any length, and the words to and as | Everything else |
| MLA | Articles, coordinating conjunctions, prepositions of any length, and the infinitive to | Everything else |
| AP (titles of works) | Articles, and prepositions and conjunctions of three letters or fewer | Principal words, and prepositions and conjunctions of four letters or more |
Take "Notes from the Underground". APA writes From, because it has four letters. Chicago and MLA write from, because it is a preposition. The title is the same and the capitalisation differs. One caveat on the table: I read APA's rule on its own site. The Chicago, MLA and AP rows come from published summaries of those manuals, and the manuals change between editions, so check the one you are bound to. AP also sets news headlines in sentence case, which makes the rule above the one for titles of books, films and songs.
What do all of them agree on?
Four things hold in every style:
- The first and last word are capitalised, even "the", "of" or "to".
- Verbs are capitalised, including the short ones: "Is", "Are", "Be", "Do". Lowercasing "is" is the most common error in hand-made title case.
- The first word of a subtitle is capitalised. APA says so explicitly for the word after a colon, and the others follow the same habit.
- Hyphenated words are a judgement call. APA capitalises the second part of a hyphenated major word, "Self-Report"; the other guides have their own hyphen rules.
If a title only contains nouns, verbs and "the", every style gives the same answer. The disagreements start at "with", "from", "over" and "into".
Which words does the case converter here leave lowercase?
The case converter keeps a fixed list of minor words lowercase unless they come first or last: a, an, the, and, but, or, nor, for, yet, so, at, by, in, of, on, to, up, via, as, from, into, onto, over, with. That list is not APA's, because APA capitalises with, from, into, onto and over. It is not Chicago's either: Chicago also lowercases longer prepositions such as "between" and "through", which this tool capitalises. It sits between the two, so a headline it produces will match some styles on some words and none of them on every word. The list is the same in English, Spanish and Portuguese pages, since the converter only knows English function words.
What does an automatic converter get wrong?
A word list cannot know what a word is doing in the sentence, and it cannot know which capitals were deliberate. I ran these through the converter:
NASA launches iPhone appbecomesNasa Launches Iphone App. Each word is lowercased first and then capitalised, so acronyms and brand spellings are flattened.log in to your accountbecomesLog in to Your Account. In "log in" the word "in" is an adverb belonging to the verb, and style guides generally capitalise it. A list sees only the spelling. The same happens with "look up".what to do with a self-report: a guide to e-mailbecomesWhat to Do with a Self-report: a Guide to E-mail. The part after the hyphen stays lowercase, and so does the "a" that opens the subtitle after the colon, which every style capitalises.- Runs of spaces collapse to one space, because the text is split on whitespace and joined back with single spaces. Line breaks are kept.
None of these is a bug in the sense of a surprise; they are what a simple word list does. Read the output before you paste it anywhere.
How do you fix what is left?
Convert first, then repair the exceptions. A find and replace that lists every match is the safe way to do it: search for Nasa with whole words on and replace it with NASA. The "Ignore case" box is off by default, so the search is case-sensitive, which is what you want when the whole point is a capital letter. The usual risk of replace-all applies here too, and the mistakes that turn a replace into cleanup are worth a minute before you run it over a long document.
Two more fixes are manual: capitalise the first word after a colon, and capitalise adverb particles like the "In" in "Log In". If the text came from a word processor and has odd characters in it, cleaning it first avoids strange results.
Should you use title case at all?
Only if something requires it. A publisher, a journal or an existing site may demand one style, and then you follow theirs. Where nobody does, sentence case, with a capital for the first word and for proper nouns, removes the whole argument, and a converter cannot get it wrong in the ways above beyond proper nouns. Whichever you pick, pick it once and apply it everywhere: a site whose headlines use two styles looks careless, and a reader does notice that more than which style it was.
If you have a heading to convert, the case converter does Title Case, Sentence case and the programming cases in the browser, and nothing you paste is sent anywhere. Treat its Title Case as a first draft and read it against the style you are following.
The same tool also turns names into camelCase and snake_case, and which convention goes where is the other half of what case conversion is for.
Frequently asked questions
Which words should not be capitalised in a title?
Articles (a, an, the), coordinating conjunctions (and, but, for, or, nor) and short prepositions (at, by, in, of, on, to, up) are lowercase in the middle of a title in every major style. Longer prepositions such as with, from and between are the contested ones: APA capitalises them, Chicago and MLA do not. The first and last word of the title are always capitalised.
Is "is" capitalised in a title?
Yes. "Is", "are", "be" and other verbs are capitalised in APA, Chicago, MLA and AP, however short they are. Lowercasing them is a common mistake because the word looks small, but it is a verb, and verbs are major words.
Should I capitalise the word after a colon in a title?
Yes, in the main styles. APA states that the first word of a subtitle, and the first word after a colon, is capitalised even if it is a minor word like "a" or "the". Many automatic converters skip this and leave it lowercase, so check the subtitle by hand.
Why does my title case converter turn NASA into Nasa?
Because it lowercases each word before capitalising its first letter, so any capitals inside the word are lost. The same happens to iPhone, McDonald and similar spellings. Convert first, then restore those words with a case-sensitive find and replace.
Last updated October 9, 2026
