Case Converter
Eleven cases, converted as you type.
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How does the Title Case option decide what to capitalise?
It follows the standard short-word rule shared by the Chicago Manual of Style and AP: articles, coordinating conjunctions and short prepositions stay lowercase unless they are the first or last word. So 'the fall of the house of usher' becomes 'The Fall of the House of Usher'. Chicago and AP disagree on prepositions of four letters or more, so check your house style if it matters.
Will it understand existing camelCase?
Yes. The programmer cases re-split the text on both punctuation and camelCase boundaries, so getUserName converted to snake_case gives get_user_name rather than getusername. Acronyms are handled too — parseHTMLDocument splits correctly into parse, HTML and Document rather than breaking on every capital letter.
What is the difference between camelCase and PascalCase?
Only the first letter. camelCase starts lowercase (userName) and is the convention for variables and functions in JavaScript, Java and Swift. PascalCase capitalises the first letter too (UserName) and is used for classes, types and React components. Mixing them up will not break most languages, but it will look wrong to anyone reading the code.
Are my proper nouns and acronyms preserved?
Not by sentence case or Title case — both lowercase everything first, so deliberate capitals in brand names, acronyms and proper nouns are lost. No automatic converter can tell that 'apple' should be Apple or that 'nasa' should be NASA. Always read the output before publishing it.
Is there a limit on how much text I can convert?
No. The conversion runs in your browser, so the only limit is your device's memory, and conversion is deferred behind your keystrokes so typing stays responsive even on very long documents. Nothing is uploaded, logged or stored, which makes it safe for unpublished drafts and client work.
About case converter
Which case should you use?
Case conventions are not decoration — most of them exist because some system somewhere refuses to accept anything else. Picking the right one is usually a question of where the text is going.
| Case | Example | Where it belongs |
|---|---|---|
| Sentence case | Convert png to webp | Body copy, UI labels, most modern headlines |
| Title Case | Convert PNG to WebP | Headlines in AP or Chicago style, book and article titles |
| camelCase | convertPngToWebp | Variables and functions in JavaScript, Java, Swift |
| PascalCase | ConvertPngToWebp | Classes and components in most languages; React components |
| snake_case | convert_png_to_webp | Python, Ruby, SQL column names |
| kebab-case | convert-png-to-webp | URLs, CSS classes, HTML attributes, filenames |
| CONSTANT_CASE | CONVERT_PNG_TO_WEBP | Environment variables and compile-time constants |
Title case is not just capitalising everything
Both the Chicago Manual of Style and AP keep short function words lowercase unless they open or close the title. This converter follows that rule, leaving articles (a, an, the), coordinating conjunctions (and, but, or) and short prepositions (at, by, in, of, on, to) in lowercase mid-title. So “the fall of the house of usher” becomes “The Fall of the House of Usher”, not “The Fall Of The House Of Usher”.
The styles disagree on where to draw the line — Chicago lowercases every preposition regardless of length, while AP capitalises anything of four letters or more. If you are writing to a house style, check which one applies before trusting any automated tool, including this one.
What happens to your existing capitals
Programmer cases (camel, Pascal, snake, kebab, constant) re-split the text from scratch, so they understand existing camelCase boundaries: feeding in getUserName and asking for snake_case gives get_user_name, not getusername. Acronyms are handled too — parseHTMLDocument splits as parse, HTML, Document.
Sentence case and Title case lowercase everything first, which means deliberate capitals are lost. If your text contains proper nouns, brand names or acronyms, check the output before using it — no automatic converter can tell that “apple” should have been Apple.
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