Zellio.io

Case Converter

Convert text to UPPER, lower, Title, Sentence or camelCase.

Processed locally — nothing is uploaded

About Case Converter

Title Case and Sentence case are the two that need checking. Short words, acronyms and proper nouns follow no single rule, so read the result before trusting it on names, brands or anything with an initialism in it.

Instantly switch text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase and more. It is the fast way to fix shouty headings, normalise data, rename variables or tidy up copy pasted from different sources.

It also works as a distraction-free scratch pad: paste, transform, copy, move on. camelCase and snake_case round-trip cleanly, but Title Case does not — capitalisation rules discard information that converting back cannot recover.

Learn how this works

Working With Text: Case, Diffs, Fonts & TranslationChange case, compare versions, generate fancy fonts, summarize and translate text — a guide to fast, private text tools.6 min read

Frequently asked questions

Which cases can it convert to?

UPPERCASE, lowercase, Title Case, Sentence case, camelCase and other common styles, applied instantly as you type or paste. Additional formats include kebab-case (used in URLs and filenames), snake_case (used in database column names and Python variables), and PascalCase (used in class names in most programming languages). The converter also includes other variations like CONSTANT_CASE, dot.case, and path/case for different coding and naming conventions. All transformations update live as you type or paste new text, so you can quickly find the format you need without guessing.

Is my text private?

No. Everything runs locally in your browser using standard web APIs — your text, files and inputs are never uploaded to a server, so the tool works even offline once the page has loaded.

Can I use it as a plain text pad?

Yes — paste, tidy and copy text freely. There is no account, no expiry and nothing is stored on a server, so your text stays completely private and local to your browser. You can keep the page open as long as you need and switch between case formats as many times as you like without any time limits or restrictions. The text remains in your browser until you close the page, and you can clear it manually or simply close the tab whenever you're done — nothing is saved or transmitted anywhere.

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