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Text case converter

Pick a mode and the text updates instantly: all caps for headlines, lowercase for tags and slugs, Title Case for names and English-style headings, sentence case for text that got typed with caps lock stuck on, and case inversion to see what iNVERTED tExT looks like.

Your data never leaves this device

Result

Characters changed

This page has no server side at all. The table you paste is parsed by JavaScript inside your own browser, the chart is drawn on a canvas element on your machine, and the export file is assembled locally. Nothing is uploaded, stored or written to any log. You can disconnect from the network after the page has loaded and everything will still work — which is the simplest way to verify the claim yourself.

Facts and limits of this method

UPPERCASE text.toUpperCase() — every letter becomes a capital
lowercase text.toLowerCase() — every letter becomes lowercase
Title Case The first letter of every word is capitalized, the rest of the word is lowercased
Sentence case The whole text is lowercased first, then the first letter of the text and the letter after every ". ", "! ", "? " is capitalized
iNVERT cAsE Every uppercase letter becomes lowercase and vice versa, character by character
Change counter The number of positions where the result character differs from the original character

When it misleads you

How it is calculated

UPPERCASE and lowercase are a direct call to JavaScript's built-in toUpperCase() and toLowerCase() on the whole string — both work fine on Cyrillic as well as Latin text.

Title Case finds every run of letters (a "word" in the broad sense) in the text and replaces each one with a capitalized-first, lowercase-rest version: word.charAt(0).toUpperCase() + word.slice(1).toLowerCase().

Sentence case first lowercases the entire text, then capitalizes the very first letter, then capitalizes the letter that follows a period, exclamation or question mark plus one or more spaces.

Case inversion walks the text character by character: if a character's uppercase form differs from itself, it's a capital and gets lowercased; if its lowercase form differs from itself, it's lowercase and gets capitalized; anything else is left as-is. The change counter compares the original and result strings position by position and counts mismatches.

Questions and answers

How is Title Case different from just capitalizing every word?

Title Case doesn't only capitalize the first letter of each word — it also lowercases the rest of the word. If a word was originally ALL CAPS, Title Case turns it into "Ordinary Capitalized Word".

Why does a capital letter appear right after a hyphen in Title Case?

The tool treats any continuous run of letters as a word. A hyphen breaks that run, so "well-known" becomes "Well-Known" — both halves of the hyphenated word get a capital.

What does the "characters changed" counter measure?

It compares the original and result text character by character and counts positions that don't match. If your text is already all uppercase and you pick UPPERCASE mode, the counter shows 0 — there's nothing to change.

Can I undo iNVERT cAsE and get the original text back?

Yes — running case inversion again on the result restores the original letters, because inversion is its own inverse operation.

Is the text sent anywhere while it's processed?

No, the whole conversion happens directly in your browser on every keystroke, the text is never transmitted anywhere.

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