Ten cases, and they are not interchangeable

Each case comes from a different convention, and picking the wrong one usually means a rename later:

  • UPPERCASE — legal copy, status labels, country codes.
  • lowercase — tags, file names on case-insensitive systems, plain labels.
  • Title Case — headings and titles. Short words such as "the", "and" or "of" stay lower-case unless they open or close the title.
  • Sentence case — one capital letter at the start of each sentence, everything else lower-case.
  • camelCase and PascalCase — Java and JavaScript naming. The first letter differs; the rest of the rule is identical.
  • snake_case — Python, database columns, environment variables.
  • kebab-case — file names, CSS classes, and the segment style most URL slugs use.
  • CONSTANT_CASE — compile-time constants and configuration keys.
  • aLtErNaTiNg — for forms and usernames that want a little noise.

How the text is split before it is converted

The converter breaks your text into words first. It separates a lower-case letter followed by an upper-case one, so myNewFile becomes three words instead of one, and it also splits runs of capitals such as HTMLParser into HTML and Parser. After that it splits on anything that is not a letter or a digit.

The consequence is worth knowing: punctuation is dropped from the joined result. hello-world in camelCase becomes helloWorld — the hyphen is gone rather than moved. The same applies to dots, slashes, colons and spaces. These cases exist to produce identifiers, not sentences.

A kebab-case result is often the last step before an address, so the URL Encoder handles the characters that still need escaping once the case is settled.

Title Case and Sentence case behave differently, because they are meant for prose. They leave your punctuation where it is and only change the letters around it.

How to use it

  1. Paste or type the text into the input panel.
  2. If the text arrived with doubled spaces or hard line breaks, the Text Cleanup tool sorts that out first.
  3. Choose the target case from the row of buttons under the input.
  4. Read the result in the output panel, then copy it or download it as a text file.

Good to know

  • Every line is converted on its own, so a list keeps its line breaks.
  • Title Case only lower-cases small words that sit in the middle of the title. The first and the last word are always capitalised, so "the art of war" becomes "The Art of War", not "The Art of war".
  • Words are split on ASCII letters and digits, so accented and non-Latin characters are treated as separators rather than as part of a word. Check the output if your text contains them.
  • The tool never inserts a space where one was not. If you need "my new file" to become one identifier, read the result before pasting it into a script.