🔤 English Case Converter

Shortcuts: Ctrl+Enter convert   Esc clear
Input chars 0 ／ words 0
Output
chars 0 ／ words 0

 What Each Mode Does

Eight transformations, one paste: UPPERCASE, lowercase, Swap Case (fixes accidental Caps Lock), Sentence case, Title Case, and the three programmer staples — camelCase, snake_case, kebab-case. Optional cleanups strip extra whitespace, punctuation, and line breaks, which rescues text pasted from PDFs. Ctrl+Enter converts, Esc clears; everything runs locally in your browser.

 Title Case Is Not One Thing

This tool capitalizes every word — simple and predictable. Publishing style guides are pickier, and they disagree with each other:

  • AP style: lowercase articles, conjunctions, and prepositions under four letters ("Gone with the Wind").
  • Chicago style: lowercase articles and all prepositions regardless of length — but capitalize both parts of hyphenated words.
  • APA style: capitalize any word of four letters or more, including prepositions ("Through", "With").
  • The safe workflow: run Title Case here for the bulk of the work, then hand-adjust the small words to your target style guide.

 Casing Pitfalls Programmers Learn the Hard Way

  • The Turkish İ problem: in Turkish locales, uppercase of "i" is "İ" (dotted) and lowercase of "I" is "ı" (dotless). Locale-sensitive case functions have broken many login systems — always case-fold user identifiers with an invariant culture.
  • The German ß: traditionally uppercases to "SS" (making round-trips lossy); an official capital ẞ exists since 2017 but adoption varies.
  • URL slugs: search engines treat hyphens as word separators and underscores as joiners — summer-sale parses as two words, summer_sale as one. Kebab-case wins for SEO.
  • Case-sensitive filesystems: Readme.md and readme.md are the same file on Windows and macOS but different files on Linux — a classic works-locally, breaks-on-deploy bug that consistent kebab-case naming avoids.

 Frequently Asked Questions

Why doesn't Title Case lowercase "the" and "of"?

By design — style guides disagree about which small words stay lowercase, so the tool capitalizes everything and leaves the style-specific exceptions to you.

How does camelCase conversion split words?

On spaces and punctuation: "user login count" → "userLoginCount". It won't re-split existing compound identifiers, so feed it space-separated words for best results.

What's Swap Case actually for?

The classic Caps Lock accident: "hELLO wORLD" swaps to "Hello World"-ish text in one click instead of retyping the paragraph.

Is there a size limit?

200,000 characters, with auto-truncation and a notice beyond that. Input stays in your browser — nothing is uploaded.

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