Chicago vs MLA Title Capitalization

Chicago and MLA lowercase the same articles and the same coordinating conjunctions, and both keep the infinitive "to" lowercase. They part company over long prepositions. Chicago lowercases a preposition only while it is short — four letters or fewer — and capitalises it from five letters up. MLA lowercases prepositions of every length. The result is a clean split that shows up in any title containing about, through, without, under or beyond, and it makes MLA the odd one out among the styles on this site rather than, as this page once had it, one of a matched pair.

Chicago Title Capitalization

CMOS 17 capitalises all major words. Short prepositions (≤4 chars) are lowercase, but longer ones like "About" and "Between" are capitalised.

Used in:Books, Publishing, History, Arts & Humanities

Chicago rules

• Capitalise all major words
• Lowercase: articles (a, an, the)
• Lowercase: coordinating conjunctions (FANBOYS)
• Lowercase: prepositions ≤4 letters (at, by, for, in, of, on, to)
• Capitalise: prepositions ≥5 letters (About, Above, Between…)
• Always capitalise first and last word
• Capitalise both parts of a hyphenated compound

MLA Title Capitalization

MLA 9th edition capitalises all principal words. Articles, prepositions, and coordinating conjunctions are lowercase in the middle of a title.

Used in:Literature, Language Studies, High School, Undergraduate

MLA rules

• Capitalise all principal words
• Lowercase: articles (a, an, the)
• Lowercase: prepositions of ANY length — "about," "between," "through," "without" all stay down (this is what separates MLA from APA, AP, and Chicago)
• Lowercase: coordinating conjunctions
• First and last word always capitalised
• Capitalise both parts of hyphenated compounds

Where Chicago and MLA Actually Disagree

The ten titles below are run through the same capitalisation engine that powers the tool on this site — not written out by hand, so they cannot drift from what you get when you paste a title in. Each set is chosen for its own pair, built around the words nearest that pair's boundary: three-letter prepositions (via, off, out, per), four-letter ones (with, from, into, over, next, like), long ones (about, during, through, without), an infinitive "to", a colon and a hyphenated compound. 6 of the 10 titles come out differently; 4 are identical. Differing rows are marked.

A Length Threshold Against a Category Rule

Chicago and MLA answer the preposition question with two different kinds of rule. Chicago measures: a preposition of four letters or fewer stays lowercase, and one of five letters or more is capitalised. MLA classifies: a preposition is a minor word and stays lowercase, however long it happens to be. Below five letters the two rules agree by coincidence, and at five letters they separate permanently.

That single divergence generates every difference in the table above. Each marked row contains one long preposition and nothing else unusual: about in An Essay About Silence (Chicago) against An Essay about Silence (MLA), and the same split on without, through, under and beyond.

The Words That Fall on Each Side

The five-letter frontier is worth memorising, because it is short and it is the only thing you need to hold in your head when moving between the two styles. Capitalised by Chicago, lowercase by MLA: about, above, across, after, against, along, among, around, before, behind, below, beside, between, beyond, during, except, inside, outside, since, through, toward, under, unlike, until and without.

Lowercase in both, because they sit under Chicago's threshold as well as inside MLA's category: at, by, in, of, on, to, up, via, off, out, per, down, from, into, like, near, next, onto, over, past, than, upon and with. The near-misses are the ones that catch people out: with and upon have exactly four letters and stay down in Chicago, while until has five and goes up.

Articles and coordinating conjunctions are lowercase in both styles, and both force a capital on the first word, the last word and the first word after a colon. The infinitive to is lowercase in both as well, which is why How to Read a Poem comes out identically. Hyphenated compounds are the one place the split escapes the preposition list: CMOS §8.157 tells Chicago to capitalise both elements of a compound unless the second is an article, a preposition or a coordinating conjunction short enough to qualify, giving The Follow-Through of a Promise, while MLA reads through as a preposition wherever it appears and returns The Follow-through of a Promise.

Where Each Style Sits Among the Others

Chicago's closest relative on this site is Bluebook, which uses the same four-letter preposition cutoff. Run a set of probe titles through both and nothing separates them: a title capitalised in Chicago is already correct in Bluebook, with the remaining legal-citation differences living in case names and abbreviations rather than in capitalisation.

MLA has no close relative at all, and this is the part of the picture that has changed. APA used to be described here as MLA's twin — the other style that lowercased prepositions of every length. It is not. APA's Section 6.17 makes every word of four letters or more a major word, so APA capitalises Without, About, Through and even With and From. That puts APA — and AP, which draws the identical line — on the far side of Chicago rather than the near side. MLA is the only style on this site that lowercases a preposition purely because it is a preposition.

So the map runs in one direction, by how eagerly each style capitalises a preposition. MLA capitalises none of them. Chicago capitalises those of five letters or more, and Bluebook matches it. APA and AP capitalise those of four letters or more, which is everything Chicago capitalises plus the four-letter band. Converting a Chicago title to MLA means lowercasing the long prepositions; converting the same title to APA means capitalising the short-but-not-tiny ones. The two conversions move in opposite directions, and a title prepared for one of them is further from the other, not closer.

That gives you a practical rule. Chicago to Bluebook: usually no edit. Chicago to MLA: scan for prepositions of five letters or more and lowercase them. Chicago to APA or AP: scan for with, from, into, over, onto, upon, past, near, next, like, down and than, and capitalise those.

One Shared Blind Spot

Both rules are written about parts of speech, and no automatic converter — this one included — can tell what part of speech a word is doing in your title. Several words on the shared lowercase list above are also ordinary verbs: like, save, past, near. When they appear as verbs mid-title, both Chicago and MLA should capitalise them, and both converters here will not. i like the way you lie comes back as I like the Way You Lie in Chicago and in MLA, and we save what we love as We save What We Love. Both are wrong by both stylebooks.

This is a shared blind spot rather than a difference, so it never shows up as a disagreement in the table above — the two styles are wrong together. The fix is manual and takes a second: after converting, read the title once and capitalise any word on the lowercase list that is carrying the sentence rather than joining it.

Neither Style Abandons Title Case in the Bibliography

This is the quiet advantage both styles share over APA, and it changes how much work a conversion is. Chicago's notes-and-bibliography apparatus sets English-language titles in headline style, the same capitalisation the title carries in the running text. MLA's Works Cited list keeps title case throughout — article title, book title and container alike. Neither style asks you to hold two capitalisations of the same title in one document.

APA does. Its References list drops article, chapter and book titles into sentence case, so a title that reads Reading Beyond the Syllabus as a heading appears as Reading beyond the syllabus three pages later in the reference entry. If you are choosing between Chicago and MLA, that whole category of error is not available to you: get the capitalisation right once and it is right everywhere in the document.

The consequence for conversion is that moving between Chicago and MLA is genuinely a capitalisation job and nothing more. Every title in the bibliography needs the same edit the titles in the text need — lowercase the long prepositions going to MLA, capitalise them coming back — and no entry needs to be recast into a different case system.

Reading a Finished Title

Given a capitalised title and no other context, you can usually place it on the Chicago-MLA axis with one pass. Find the longest lowercase word that is not at the start or the end of the title and not immediately after a colon. If it is a preposition of five letters or more — about, under, through, without, beyond — the title is MLA, or at least is not Chicago. If every lowercase word is four letters or fewer, the title is consistent with Chicago.

The test fails only when a title contains no long preposition in a middle position, which is common in short titles and rare in long ones. How to Read a Poem and Cooking with Fire are identical in both styles and tell you nothing. An Essay about Silence tells you everything in one word.

Note the direction of the asymmetry: there is no word MLA capitalises that Chicago lowercases. Chicago's output is always the same as MLA's or has more capitals, never fewer. If you find a title where MLA is the more capitalised of the two, one of them has been applied wrongly.

Which One Should You Use

Use Chicago for books, publishing, history and general non-fiction, where it is the house standard and its capitalised long prepositions are what an editor expects to see. Use MLA for literature, language studies and English coursework at school and undergraduate level, where a capitalised Through mid-title will be marked as an error. If you are converting a manuscript from one to the other, you do not need to re-read the whole title: scan for prepositions of five letters or more and change only those.

See Both Styles Applied to Your Title

The fastest way to understand the difference between Chicago and MLA is to enter your own title and see both results. Use the style comparison tool to see your title in all nine styles simultaneously, including both Chicago and MLA. Or open either style guide, each of which has the capitalizer built in:

• Chicago title capitalization rules and converter
• MLA title capitalization rules and converter

Related Comparisons

• APA vs Chicago title capitalization
• APA vs MLA title capitalization
• APA vs AP title capitalization

Frequently Asked Questions

What is the difference between Chicago and MLA title case?

The key difference is how they handle prepositions. Chicago lowercases only short prepositions (≤4 letters) and capitalizes longer ones like "About," "Between," and "Through." MLA lowercases all prepositions regardless of length. A title with longer prepositions will look different in Chicago vs MLA.

Do Chicago and MLA capitalize titles the same way?

Not quite. They agree on most words — both capitalize nouns, verbs, adjectives, and adverbs. The difference appears in longer prepositions: "Between," "Through," "Without," "Against" are capitalized in Chicago but lowercase in MLA.

Which style should I use for book titles?

Chicago is the standard for most book publishing in the US. MLA is used for literature and humanities courses but is less common in professional publishing. If you are publishing a book, Chicago is almost certainly the right choice.

Which style should I use for essays?

MLA is standard for essays in English literature and language courses. Chicago is standard for history and humanities at many universities. Check your course, department, or publication requirements to confirm which applies.

How do Chicago and MLA handle prepositions?

Chicago lowercases prepositions of four or fewer letters (at, by, for, in, of, on, to, up, from, into, with) but capitalizes longer ones (About, Above, Between, Through, Without). MLA lowercases all prepositions regardless of length — the only style here that does, and the reason Chicago is its nearest match.

Can I convert the same title in Chicago and MLA style?

Yes. The Compare Styles tool shows Chicago and MLA (and all 7 other styles) side by side for any title.

Can I compare Chicago and MLA title case side by side?

Yes. Enter any title in the comparison tool and both results appear in the same table.