Case Converter
Convert text between uppercase, lowercase, camelCase, and more
Converts text to eight cases: four for writing (UPPERCASE, lowercase, Title Case, Sentence case) and four for code (camelCase, PascalCase, snake_case, kebab-case). Paste the text and pick a case; the converted text updates as you type. Title Case follows the Chicago, AP, APA or MLA style guide, or capitalises every word.
How each case treats your text
UPPERCASE and lowercase change letters only and keep everything else as it is. Sentence case lowercases the text, then capitalises the first letter and the first letter after each full stop, question mark or exclamation mark — so names and “I” end up lowercase and need fixing by hand.
Title Case capitalises the principal words and lowercases the small ones the chosen style names (listed under title case styles below), keeping punctuation, spacing and line breaks. It works in any script with capital letters and treats “don't” as one word.
The four code cases build an identifier from the words of the text: letters and digits in any script, with everything else dropped. An identifier that is already in camelCase or PascalCase is split where its case changes, so “XMLHttpRequest” becomes “xml_http_request” in snake_case.
Examples
One title in each style
- Text
- a walk with friends through the woods: what it is made of
- Chicago
- A Walk with Friends Through the Woods: What It Is Made Of
- AP
- A Walk With Friends Through the Woods: What It Is Made Of
- APA
- A Walk With Friends Through the Woods: What It Is Made of
- MLA
- A Walk with Friends through the Woods: What It Is Made Of
- Every word
- A Walk With Friends Through The Woods: What It Is Made Of
“With” has four letters and “through” seven, so the styles split on them; only APA leaves the last word lowercase.
Renaming an identifier
- camelCase
- userProfileID
- snake_case
- user_profile_id
- kebab-case
- user-profile-id
- PascalCase
- UserProfileId
The words come from the changes of case, and the capitals of “ID” stay one word.
Every case on one example
| Case | Result | Common use |
|---|---|---|
| UPPERCASE | THE QUICK BROWN FOX. JUMPS OVER 2 DOGS | Headings, emphasis, constants |
| lowercase | the quick brown fox. jumps over 2 dogs | Normalising text, emails, tags |
| Title Case (Chicago) | The Quick Brown FOX. Jumps over 2 Dogs | Titles, names, headings |
| Sentence case | The quick brown fox. Jumps over 2 dogs | Ordinary prose, UI labels |
| camelCase | theQuickBrownFoxJumpsOver2Dogs | JavaScript and Java variables |
| PascalCase | TheQuickBrownFoxJumpsOver2Dogs | Class and component names |
| snake_case | the_quick_brown_fox_jumps_over_2_dogs | Python, database columns |
| kebab-case | the-quick-brown-fox-jumps-over-2-dogs | URLs, CSS classes, file names |
Title case styles
- Chicago (18th edition, the default) — lowercases a, an, the; and, but, for, or, nor; to; as; and prepositions of four letters or fewer, such as “with” and “from”.
- AP — lowercases articles, and conjunctions and prepositions of three letters or fewer.
- APA — lowercases articles, and conjunctions and prepositions of three letters or fewer, including “up” and “off”. A small last word stays lowercase.
- MLA — lowercases articles, coordinating conjunctions, “to” and prepositions of any length.
- Every word — capitalises every word.
In every style, each line is its own title. The first word is always capitalised, and so is the last word except in APA. A colon, question mark or exclamation mark followed by a space, or an em dash, starts a subtitle with the same rules; so does an en dash with spaces around it, but not one in a range such as “1990–2000”. A full stop does not, so “U.S. and Canada” keeps “and” lowercase.
Each part of a hyphenated word is capitalised unless it is a small word in the style (“Up-to-Date”), and a hyphenated word that ends a title has its last part capitalised. Some style guides make exceptions for prefixes; the tool applies the same rule after every hyphen.
Words already capitalised past their first letter, such as NASA or iPhone, are kept as written, unless the whole line is in capitals. The styles treat a word differently by its role in the sentence, which a word list cannot tell: the verb in “What I Like About You” reads as the preposition “like”, and a word such as “since” used as a conjunction is treated as a preposition. These need fixing by hand. Up, down, out and off are capitalised outside APA, because in titles they are usually part of a phrasal verb (“Set Up”).
Sources
- Title Case Capitalization — APA Style
- Capitalization, Titles (Q&A) — The Chicago Manual of Style
- Why does the MLA capitalize certain words in titles? — MLA Style Center
- AP Stylebook: composition titles (subscription) — The Associated Press
Reviewed
See also
- Find and Replace — to change specific words rather than the whole text's case.