APA vs AP Title Capitalization

APA and AP produce identical title case. Both define their minor words the same way — articles, plus prepositions and conjunctions of three letters or fewer — which means both capitalise every word of four letters or more. There is no title you can construct that separates them, and the live table below is a test of that claim rather than a display of differences. What actually separates APA from AP is not the algorithm. It is the document each one governs: APA is a documentation system whose reference list drops out of title case altogether, and AP is a newsroom style whose headlines are increasingly not in title case at all.

APA Title Capitalization

APA 7 (§6.17) capitalizes major words — nouns, verbs, adjectives, adverbs, pronouns — and every word of four letters or more, including prepositions such as "With," "From," "About," and "Between." Only articles and conjunctions or prepositions of three letters or fewer are lowercase, and never as the first or last word.

Used in:Psychology, Social Sciences, Education, Business

APA rules

• Capitalise all major words (nouns, verbs including linking verbs, adjectives, adverbs, pronouns)
• Capitalise every word of four letters or more — including prepositions: "With", "From", "About", "Between", "Through", "Without"
• Lowercase: articles (a, an, the)
• Lowercase: conjunctions of three letters or fewer (and, but, or, nor, for, so, yet)
• Lowercase: prepositions of three letters or fewer (of, on, in, to, at, by, up, as, via, off, out, per)
• Always capitalise first and last word
• Always capitalise the word after a colon

AP Title Capitalization

AP style capitalizes words of 4 or more letters. Short prepositions, articles, and conjunctions under 4 letters are lowercase.

Used in:Journalism, News, PR, Marketing

AP rules

• Capitalise words of 4+ letters, whatever their part of speech
• Lowercase: articles (a, an, the)
• Lowercase: prepositions of fewer than 4 letters (of, on, in, to, at, by, up, as, via, off, out, per) — the rule is a letter count, not a fixed list
• Lowercase: coordinating conjunctions of fewer than 4 letters (and, but, or, nor, for, so, yet)
• First and last word always capitalised

Where APA and AP 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. APA and AP produce identical output on all 10 of them. Not one word is capitalised differently.

The Same Rule, Written Twice

APA states the rule in terms of word classes and then attaches a length test to it. Section 6.17 treats as major words all nouns, verbs, adjectives, adverbs, pronouns — and all words of four letters or more. Minor words are the articles and any conjunction or preposition that is short, which APA defines as three letters or fewer. AP states the rule as a measurement: capitalise words of four or more letters, and lowercase articles, conjunctions and prepositions below that.

Those two sentences describe the same boundary. Both styles lowercase exactly this set when it appears mid-title: a, an, the; and, but, for, nor, or, so, yet; as, at, by, in, of, on, to, up; and the three-letter prepositions off, out, per, pro, via, cum, ere, mid and qua. Everything else takes a capital. Both also force a capital on the first word, the last word and the first word after a colon.

There is no residue. Because the lowercase sets are the same and the positional rules are the same, the output is the same — not usually, not for ordinary titles, but for every input. The table above is not a small sample that happened to agree; it is a demonstration that there is nothing left to disagree about.

Why You Will See Claims That They Differ

Plenty of comparisons assert that APA and AP run on incompatible logics — that AP counts letters while APA reads grammar and lowercases prepositions of any length. That framing is tidy, and it is wrong. It comes from a misreading of APA §6.17, which defines words of four letters or more as major words, exactly as AP does. Read correctly, the two rules converge: Living With Uncertainty in both, not Living with Uncertainty in one.

A second source of phantom differences is the converters themselves. A tool that implements AP as a fixed list of short words rather than as a letter count will capitalise off, out, per and via — words of three letters that the four-letter rule keeps lowercase. Two tools wrong in opposite directions will manufacture a disagreement that neither stylebook contains.

So this page says the unhelpful-sounding thing that happens to be true: for title case, APA and AP agree. A comparison that invents a difference in order to have something to compare is worse than no comparison at all, because a reader acts on it.

The Four Words That Expose a Broken Converter

If you want to test any title capitaliser — this one included — against the four-letter rule, use the three-letter prepositions that look long enough to capitalise but are not. The Art of Writing off the Cuff, Coming out of the Dark, A Report per Capita and Travel via Rail are correct APA and correct AP, with the small word down in all four. A tool that returns Off, Out, Per or Via in those positions is applying a word list rather than the rule.

The mirror test is the four-letter band, where the capital is correct and looks wrong to most people: Notes From Underground, Living With Uncertainty, Stepping Into the Unknown. Readers who learned "lowercase the little words" tend to flag those as errors. They are not, in either style.

Two further agreements are worth naming because they get argued about. AP does not capitalise To in an infinitive — to is two letters and the rule is about letter count, with no infinitive exception — so How to Write a News Lede is correct in both styles. And a hyphenated compound is handled the same way in each: The Come-From-Behind Win capitalises From in APA and in AP alike, because four letters is four letters wherever the word sits.

Where APA and AP Actually Diverge

The two styles are not interchangeable; they simply do not differ where this page used to say they did. They differ in domain. APA is a documentation system for scholarly writing. Title case governs the paper title, the headings, the table and figure titles — and then the reference list leaves title case entirely. Article, chapter and book titles in an APA References entry are set in sentence case: first word, first word after a colon, proper nouns, nothing else. The same string can therefore appear twice in one document in two different forms — Living With Uncertainty as the paper's title, Living with uncertainty in the reference entry for someone else's article. There is no AP counterpart to this, because AP has no reference list.

AP is a newsroom style, and its centre of gravity has moved. Headline case is still the default in print and in wire copy, but a large share of digital news desks now set headlines in sentence case, on the reasoning that a headline behaves more like a sentence than a label on a screen. If you are writing for a specific outlet, its house sheet decides that question and this page does not. What matters here is that the choice is between title case and sentence case — not between AP's title case and APA's, which are the same thing.

The two styles also diverge across the rest of the sentence in ways that have nothing to do with capitalisation: AP spells out numbers below ten and skips the serial comma, APA uses numerals from ten up and keeps it. Those differences are real and will show up in any document you convert. Your title will not be among them.

Telling Which Style a Title Came From

You cannot. That is worth stating directly, because "which style is this?" is a question people ask of a finished title and one that has an answer for most other pairs on this site. Between APA and AP it does not. A correctly capitalised title carries no information about which of the two rules produced it, and any tool or editor claiming to detect the difference from the string alone is guessing.

What you can read a title against is the styles that sit elsewhere on the scale. MLA lowercases prepositions of every length, so a lowercase without or about mid-title rules out both APA and AP. Chicago and Bluebook lowercase four-letter prepositions, so a lowercase with, from, into or over in the middle of a title rules them out too. A capital on all of those and a lowercase on off, out, per and via narrows it to APA-or-AP and stops there.

To go further you have to look outside the title. A reference list in sentence case, a running head, or numbered headings mean APA. A dateline, a byline, cutlines under photos or a subhead written as a sentence mean AP. The document tells you what the title cannot.

Which One Should You Use

For the title itself, the question does not arise — pick either and the string is the same. Pick by document. Use AP for news writing, press releases, marketing copy and anything destined for a newsroom CMS, and check whether that outlet has moved its headlines to sentence case before you deliver. Use APA for psychology, education, nursing, social science and business academic work, where what you are really adopting is the reference-list system rather than the headline rule.

The practical payoff of the two styles agreeing is that a title written for one place can be reused in the other without editing. If a study's headline goes out to a news outlet and its abstract goes into a journal, the capitalised title is portable. Only the reference entry needs a second, sentence-cased version.

See Both Styles Applied to Your Title

The fastest way to understand the difference between APA and AP 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 APA and AP. Or open either style guide, each of which has the capitalizer built in:

• APA title capitalization rules and converter
• AP title capitalization rules and converter

Related Comparisons

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

Frequently Asked Questions

What is the difference between APA and AP title case?

Despite the confusingly similar names, their title case rules land in the same place. AP (Associated Press) capitalizes all words of four or more letters, and APA (American Psychological Association) §6.17 counts "all words of four letters or more" as major words — so "From," "With," and "Into" are capitalized in both. The real difference is scope: APA also governs reference lists, where titles drop to sentence case, while AP governs headlines and composition titles.

Does AP capitalize more words than APA?

No. Both capitalize prepositions of four or more letters — "From," "With," "Over," "Into," "About" — and both lowercase articles and short conjunctions and prepositions. For title case, the two produce the same number of capitals on the same words.

How does APA treat prepositions in titles?

APA lowercases prepositions of three letters or fewer — of, in, at, by, up, via. Prepositions of four letters or more are major words and are capitalized: "Between," "Through," "Without," "About," "During."

How does AP treat prepositions in titles?

AP capitalizes all words of four or more letters, so prepositions of four or more characters — From, With, Into, Over, Than, About, Among, Between, Through — are all capitalized. Only prepositions of three or fewer characters are lowercase.

Should I use APA or AP for journalism?

Use AP for journalism. The Associated Press Stylebook is the standard for newspapers, news websites, press releases, and most media outlets. APA is designed for academic research papers — it is not the journalism standard.

Should I use APA or AP for academic writing?

Use APA for academic writing in the social and behavioral sciences. AP is not an academic style guide — it is designed for fast-paced journalism. Academic journals, theses, and institutional papers in psychology and education use APA.

Can I convert the same title in APA and AP style?

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

Can I compare APA and AP title case side by side?

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