AP Title Capitalization Rules
AP style capitalizes words of 4 or more letters. Short prepositions, articles, and conjunctions under 4 letters are lowercase.
Word-by-word explanation
AP Capitalization 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
Source for These AP Rules
Primary source
The Associated Press Stylebook
- Published by
- The Associated Press
The AP Stylebook is revised on a rolling basis rather than issued as a numbered edition, so no edition number or year is claimed here. The engine implements the Stylebook’s length-based headline rule: capitalize words of four or more letters, and lowercase shorter articles, conjunctions, and prepositions.
TitleCasePro is not affiliated with, endorsed by, or a substitute for the publisher above. For how these rules were turned into code, which edge cases the engine decides for you, and how the results are tested, read the methodology. If you believe a rule here is wrong, tell us and cite the section you are reading.
Where AP Title Case Is Used
AP title capitalization is the standard for Journalism, News, PR, Marketing writing. When your work will be reviewed, published, or cited within these fields, using the correct capitalization shows attention to detail and compliance with professional standards. If your publication specifies a house style, follow that preference over the base standard.
How AP Style Works in Practice
AP title case is defined by the Associated Press Stylebook and is the standard for US newspapers, wire services, broadcast journalism, and most digital news organizations. AP uses a simple length-based rule: capitalize any word of four or more letters, regardless of its grammatical category. This means prepositions like "with," "from," "into," and "over" — which Chicago and MLA lowercase — are capitalized in AP. The rule is designed to be fast and easy to apply under deadline pressure. Journalists can apply it without consulting a style guide: count the letters, and capitalize at four or more. The threshold exists precisely to remove judgement calls: on deadline, nobody has time to decide whether "with" is doing prepositional work or riding along with a verb, so AP swaps a grammar question for a counting question and every desk lands on the same answer. Where you apply it matters just as much. AP title case belongs to formal composition titles — books, films, albums, songs, reports — while AP news headlines have moved steadily toward sentence case, which scans faster on a phone and reads less like shouting in a search result or social preview. Plenty of newsrooms run a hybrid of the two, so check your own publication's guide before applying either pattern across the board.
How the AP Capitalizer Works
Paste your title into the tool above. AP is already selected, so the result appears immediately. Click "Explain" to see the rule applied to each word. Use the copy button or press ⌘↵ to copy the output. Everything runs in the browser — no account, no signup, no data sent to a server.
To convert a list of titles at once, the batch capitalizer imports CSV and TXT files. To see one title in all nine styles simultaneously, use the style comparison tool.
AP Title Case Examples
These examples are generated in real time by the same engine that powers the tool above — every result is guaranteed to match the tool's output.
| Original (lowercase) | AP Style |
|---|---|
| the quick brown fox jumps over the lazy dog | The Quick Brown Fox Jumps Over the Lazy Dog |
| a guide to writing about the world | A Guide to Writing About the World |
| why sleep is important for students | Why Sleep Is Important for Students |
| learning through failure and success | Learning Through Failure and Success |
| notes on the art of writing without fear | Notes on the Art of Writing Without Fear |
| how to capitalize titles in academic writing | How to Capitalize Titles in Academic Writing |
| the effects of social media on mental health | The Effects of Social Media on Mental Health |
| introduction to machine learning with python | Introduction to Machine Learning With Python |
Common Edge Cases in AP Style
- "With" (4 letters) is capitalized in AP — this surprises writers familiar with Chicago or MLA, which both lowercase it. APA capitalizes it too, because APA draws its line at four letters as well.
- "From," "into," "over," "upon," "like," and "onto" (all 4 letters) are capitalized in AP.
- "To" (2 letters) stays lowercase, including in infinitives: "How to Write a Book." AP applies its length rule with no infinitive exception.
- "The" (3 letters) stays lowercase mid-title; "An" (2 letters) stays lowercase.
- Many AP news websites use sentence case for headlines, while formal composition titles use AP title case.
- A house rule beats the general rule: if your publication or CMS specifies sentence-case headlines, that governs the headline field only — the titles of books, films, songs, and reports named inside the story still take AP title case.
- The length threshold ignores part of speech on purpose. AP asks how long a word is, not what job it is doing, which is what makes the rule fast enough to apply under deadline.
How AP Differs From APA
AP's closest match is APA, which is not where most writers would look. Both draw the line at four letters — AP capitalizes words of four or more letters, and APA §6.17 counts "all words of four letters or more" as major words — so the two produce identical title case: "Learning Without Fear," "Letters From Home During Wartime," "How to Write a Book." The difference is what each style covers, not how it capitalizes. AP governs news headlines and formal composition titles; APA additionally governs reference lists, where article, chapter, and book titles drop to sentence case. NY Times house style is the next closest to AP and differs only on a handful of three-letter prepositions such as "via," "off," and "out," which NY Times capitalizes.
AP Title Capitalization FAQ
Common questions about AP title case rules and the AP capitalizer.
AP title capitalization follows the Associated Press Stylebook. It uses a simple length rule: capitalize all words of four or more letters. Articles, prepositions fewer than four letters, and coordinating conjunctions are lowercase. This makes AP one of the easiest styles to apply consistently.
Use AP title case for newspaper articles, wire service content, press releases, digital news, and content marketing. The AP Stylebook is the standard guide for US journalism and much of the public relations industry.
All words of four or more letters are capitalized. This includes nouns, verbs, adjectives, adverbs, and prepositions of four or more letters — "From," "With," "Into," "Over," "Than," "Like." The first and last word are always capitalized.
Articles (a, an, the), prepositions of fewer than four letters (at, by, of, on, to, up), coordinating conjunctions (and, but, or, nor, for, so, yet), and the particle "as" are lowercase in the middle of an AP title.
No. Articles (a, an, the) are lowercase in AP title case in the middle of a title. "A" or "The" is capitalized only when it is the first word of a title.
Coordinating conjunctions (and, but, or, nor, for, so, yet) are lowercase. Longer conjunctions of four or more letters (although, because, unless, while) are capitalized under the 4+ letter rule.
Short prepositions (fewer than four letters) — at, by, of, on, to, up — are lowercase. Prepositions of four or more letters — From (4), With (4), Into (4), Over (4), Than (4), About (5) — are all capitalized because AP's rule is based purely on word length.
Yes. The first word of any AP title is always capitalized regardless of its part of speech or length.
Yes. The last word of an AP title is always capitalized.
AP's defining rule is the 4+ letter threshold, applied to every word regardless of part of speech. AP capitalizes "From," "With," and "Into" — all of which are lowercase in Chicago and MLA. APA uses the same four-letter line, so AP and APA title case come out identical.
Yes. Use the AP title capitalizer to convert any title instantly with a full explanation.
Yes. The Compare Styles tool shows all 9 styles side by side.
Yes. TitleCasePro's AP mode follows the AP Stylebook length rule. Use the Title Capitalizer or Batch Capitalizer for large lists.
The AP title capitalizer applies Associated Press Stylebook capitalization rules to any title instantly. AP style is standard for journalism, news writing, and digital media. Select AP, paste your title, and the result appears immediately.
AP style capitalizes all words of four or more letters and lowercases articles (a, an, the), prepositions of fewer than four letters, and coordinating conjunctions. For example: "The Girl With the Dragon Tattoo" — "With" is capitalized (4 letters), "the" stays lowercase.
Yes. TitleCasePro follows the AP Stylebook length-based rule: words of four or more letters are capitalized. Short articles, prepositions, and conjunctions are lowercase.
AP capitalizes every word of four or more letters, including prepositions like "From," "With," "Into," and "Over." It lowercases articles (a, an, the), short conjunctions (and, but, or), and prepositions of three or fewer letters (at, by, of, on, to, up).
Yes. Click "Explain" to see each word labeled — for example, "from — 4 letters, capitalized per AP style" or "the — article, lowercase per AP style."
Yes. Use the Copy button next to the output or press ⌘↵ to copy the AP-formatted title to your clipboard.
Yes. The Compare Styles tool shows AP alongside APA, Chicago, MLA, and all other styles at once.
Yes. AP style is the standard for newspaper and digital news article headlines. Paste your headline and the tool applies correct AP capitalization.
Yes. If your publication or class follows AP style, the capitalizer handles your essay title correctly according to AP rules.
Yes. Some trade publishers and media companies follow AP for book titles. The tool applies AP rules accurately.
Yes. AP capitalization applies to section headings and subheadings in journalism-style content. The tool handles these the same way it handles article titles.
Yes. Completely free with no account, signup, or usage limit.
Yes. Runs entirely in your browser — no server upload required.