Which style should I use?

APA and AP both lowercase short prepositions and articles of three letters or fewer; Chicago and MLA lowercase every preposition regardless of length. If a publication or professor has assigned a style guide, use that one. Otherwise, APA is a safe default.

Why does it keep “NASA” or “iPhone” unchanged?

A word with a capital letter after its first letter (an acronym, or a stylised brand name) is treated as intentional casing and left exactly as typed by default. Untick “Keep acronyms and brand names” to force every word through the same capitalization rule.

Does it handle titles that are already in ALL CAPS?

Yes. An all-caps line carries no information about which words should be capitalized, so it is lowercased first and then title-cased normally. That also lowercases acronyms in the line, so retype those in mixed case if you need them kept.

What happens to hyphenated words?

Each part of a hyphenated compound is capitalized on its own terms (for example, “Self-Driving” and “State-of-the-Art”), matching how style guides treat compound modifiers in titles.

Title Case Converter: APA, Chicago, AP, MLA

How to use

Paste one title per line; each line is converted on its own.
Pick a Mode: Title Case, Sentence case, UPPERCASE, lowercase, Capitalize Each Word, aLtErNaTiNg cAsE or tOGGLE cASE.
For Title Case, choose the Title case style: APA, Chicago, AP or MLA. The result updates as you switch, so you can compare them.
Leave Keep acronyms and brand names (NASA, iPhone) as typed on unless you want every word forced through the rule.
Copy to clipboard, or Ctrl+Enter from the input box.

What “Title Case” actually means

Title case is not simply capitalizing every word. Style guides agree that the first and last word of a title are always capitalized, and that short articles (a, an, the) and coordinating conjunctions (and, but, or) stay lowercase in the middle of a title. Where they disagree is prepositions: APA and AP capitalize any word of four or more letters (so “With” is capitalized but “to” is not), while Chicago and MLA lowercase every preposition no matter its length.

Getting this right by hand means checking a list of exceptions for every word, which is exactly the kind of small, repetitive rule-following that is easy to get slightly wrong under a deadline. This tool applies the rule set consistently and instantly as you type, one line at a time, and links the APA rules it follows at the bottom of the page. Converting a variable or function name instead of a headline is a different job with different rules. Use the Code Case Converter for camelCase, snake_case and the like.

Example: the same title, four ways

Starting from a walk through the park with dogs:

Style	Result
APA	`A Walk Through the Park With Dogs`
Chicago	`A Walk through the Park with Dogs`
AP	`A Walk Through the Park With Dogs`
MLA	`A Walk through the Park with Dogs`

Notice “Through” and “With” only capitalize under APA/AP, since Chicago and MLA lowercase prepositions of any length.

Options explained

Mode: Title Case applies the selected style guide's rules to each line.
Sentence case lowercases everything, then capitalizes the first letter of each sentence (after ., ! or ?) and the pronoun I. Acronyms are lowercased too: The NASA Team becomes The nasa team.
UPPERCASE / lowercase change every letter and ignore word boundaries entirely.
Capitalize Each Word capitalizes the first letter of every word and every hyphenated part, with no exceptions: State-Of-The-Art Thing. Use it for names and menu labels, not titles.
aLtErNaTiNg cAsE / tOGGLE cASE are novelty modes. Alternating counts letters only, so spaces and punctuation do not reset the pattern; Toggle flips the case of every letter.
Title case style: APA / Chicago / AP / MLA. APA and AP lowercase only minor words of three letters or fewer (of, to, in, per, via), so With and From are capitalized. Chicago and MLA lowercase every preposition whatever its length (with, through, between). All four capitalize the first and last word and the word after a colon.
Keep acronyms and brand names (NASA, iPhone) as typed leaves any word alone that has a capital letter after its first letter. Untick it to force iPhone → Iphone and macOS → Macos.

Edge cases and common errors

ALL-CAPS input loses its acronyms. An all-caps line carries no casing information, so it is lowercased first: NASA LAUNCHES ROCKET → Nasa Launches Rocket. Retype the acronym in a mixed-case line and it survives: NASA launches rocket → NASA Launches Rocket.
Subtitles work. The word after :, —, –, ?, ! or . is always capitalized: who is it? the story of a man → Who Is It? The Story of a Man.
Hyphenated compounds are split and each part follows the minor-word rules, so a state-of-the-art self-driving car → A State-of-the-Art Self-Driving Car under every style.
A leading quote or bracket is skipped when capitalizing: "the end" of an era → "The End" of an Era.
vs. and as are treated as minor words: cats vs. dogs as pets → Cats vs. Dogs as Pets.
Accented and non-Latin letters capitalize correctly (über die brücke → Über Die Brücke), but the minor-word lists are English only, so die is treated as an ordinary word.
Sentence case does not know proper nouns. Names, places and acronyms come out lowercase and need fixing by hand.
Numbers are left alone: top 10 tips for 2024 → Top 10 Tips for 2024.
Empty lines stay empty, so a pasted list keeps its spacing.

Do the same thing in code

The built-in helpers capitalize every word and know nothing about style guides, which is usually not what a title needs:

Python

"the art of war".title()        # 'The Art Of War' (capitalizes "Of")
"state-of-the-art".title()      # 'State-Of-The-Art'
# for real style-guide rules: pip install titlecase

JavaScript

text.replace(/\b\w/g, (c) => c.toUpperCase());   // same naive result
// for real style-guide rules: npm install title-case

Runs entirely in your browser: this page is a static file with no server behind it, so nothing you paste can be uploaded. Last reviewed 18 September 2026 by Parthesh Gupta. Implements APA Style: title case.