Text Case Conversion: Upper, Lower, Title Case and More
Learn about different text case types and how to convert between them. Covers uppercase, lowercase, title case, sentence case, camelCase, snake_case, and more.
Table of Contents
- Common Text Case Types
- Case in Writing and Publishing
- Case in Programming
- When to Use Each Case
- Case Conversion Tips
Common Text Case Types
| Case Type | Example | Description |
|---|---|---|
| UPPERCASE | HELLO WORLD | All letters capitalized |
| lowercase | hello world | All letters in lowercase |
| Title Case | Hello World | First letter of each word capitalized |
| Sentence case | Hello world | Only first word capitalized |
| aLtErNaTiNg CaSe | hElLo WoRlD | Alternating upper and lower |
| Inverse Case | hELLO wORLD | Opposite of original case |
Case in Writing and Publishing
Different style guides have different rules for capitalization:
- AP Style (journalism): Uses title case for headlines. Capitalize words with four or more letters.
- Chicago Manual of Style: Uses title case for book titles. Capitalizes nouns, pronouns, verbs, adjectives, and adverbs.
- APA Style (academic): Uses sentence case for article titles and references, but title case for book titles.
- MLA Style (humanities): Uses title case for all titles in citations and references.
When in doubt, check which style guide your publication or institution requires.
Case in Programming
Case conventions in programming are not just aesthetic — they carry meaning:
- camelCase:
getUserData— standard for JavaScript, Java, and C# functions and variables. - PascalCase:
UserProfile— used for classes, components, and constructors. - snake_case:
get_user_data— standard in Python, Ruby, and database naming. - kebab-case:
user-profile— used in URLs, CSS classes, and file names. - SCREAMING_SNAKE_CASE:
MAX_RETRY_COUNT— used for constants in most languages.
When to Use Each Case
- UPPERCASE: Acronyms (NASA, HTML), emphasis in casual writing, button labels.
- lowercase: Body text, informal communication, modern brand names (eBay, iPhone).
- Title Case: Headlines, book titles, page titles, navigation menu items.
- Sentence case: Subheadings, UI labels, article titles (in some styles), email subjects.
- camelCase: JavaScript variables and functions, Java methods.
- snake_case: Python variables, database column names, environment variables.
Case Conversion Tips
- Preserve acronyms: When converting to title case, keep acronyms like HTML, API, and CSS in uppercase.
- Handle edge cases: Words like "iPhone" and "macOS" have unusual capitalization that automated tools may mishandle.
- Check proper nouns: Names, places, and brands should always retain their correct capitalization regardless of case conversion.
- Use online tools: A case converter tool handles the rules for each case type automatically, saving time and reducing errors.
Try it now: Open the Case Converter →
Paste your text to instantly convert between uppercase, lowercase, title case, and more.
Frequently Asked Questions
What is title case?
Title case capitalizes the first letter of most words in a title. Articles (a, an, the), short prepositions (in, on, at), and conjunctions (and, but, or) are typically left lowercase unless they are the first word. Different style guides have slightly different rules.
What is the difference between sentence case and title case?
Sentence case capitalizes only the first word and proper nouns, like a normal sentence: 'The quick brown fox jumps.' Title case capitalizes most words: 'The Quick Brown Fox Jumps.' Sentence case is used in APA style; title case is used in Chicago and AP style.
When should I use camelCase vs snake_case?
camelCase is the convention in JavaScript, Java, and C# for variable and function names. snake_case is used in Python, Ruby, and database columns. kebab-case is used in URLs and CSS. The choice depends on the programming language and team conventions.