Case Converter

Change text to upper, lower, title, sentence, camel, snake or kebab case in your browser.

Free, no limit Nothing uploaded Works offline No sign-up

Eight cases, and knowing which one you want

Changing case sounds trivial until you need a specific convention. Title Case for a headline, sentence case for a paragraph, camelCase for a JavaScript variable, snake_case for a Python one, kebab-case for a URL or a CSS class.

Each has a rule and this tool applies it properly rather than simply uppercasing the first letter of everything. Sentence case lowercases the rest of the text before capitalising after each full stop, so shouted text comes back readable. camelCase strips punctuation and joins the words, which is what a variable name requires.

Everything updates as you type, with no button to press. Paste a heading, watch it change, copy the version you wanted.

A line of text shown in several different letter cases

How to use it

Paste into the left box and the result appears in the right one as you type. Change any option and it recalculates immediately.

Copy puts the result on your clipboard and confirms it did. Download saves it as a file, which is the easier route when the output is long enough that selecting it by hand is a nuisance. Clear empties the boxes and puts the cursor back where you need it.

Where a sample button appears, it loads a small realistic example. It is there so you can see what the tool expects before pasting your own material, which is quicker than reading a description of the input format.

Keyboard and mobile

The text areas are ordinary form fields, so every shortcut your system already has works: select all, undo, redo, and paste without formatting. Tab moves between the panes and the controls in the order you would expect, and every control is reachable without a mouse.

On a phone the panes stack rather than sitting side by side, and the text areas grow to a comfortable height. Spellcheck and autocorrect are switched off in them, because a tool that silently capitalises your case converter input is worse than useless.

If something looks wrong

When the result is not what you expected, the message under the boxes is the first thing to read. It reports what happened rather than a generic failure, so a malformed input names the line to look at and a successful run reports what it did, such as how many lines it kept or how many replacements it made.

A count of zero is informative in itself. It usually means the input did not contain what you thought it did, most often because of capitalisation or an invisible trailing space, both of which are far more common in pasted data than people expect.

Nothing is corrected silently. If the input cannot be handled, the output is left empty and the reason is stated, rather than a partial result being returned that looks plausible and is wrong. A tool that guesses is worse than one that says it could not.

Which convention goes where

These are near universal in the places listed, and using the wrong one marks code out immediately.

  • camelCase, JavaScript and Java variables and functions.
  • PascalCase, class names in most languages, and React components.
  • snake_case, Python variables and functions, and most SQL column names.
  • kebab-case, URLs, CSS class names and HTML attributes, none of which permit underscores comfortably.
  • SCREAMING_SNAKE_CASE, constants and environment variables, everywhere.
  • Title Case, headlines and buttons in most style guides, though several major publications now prefer sentence case.

Title case has genuine disagreement inside it. Some guides capitalise every word, others leave small words such as of, the and and in lower case unless they open the line. This tool capitalises every word, which is the simpler and more common of the two.

Conventions worth following

Most of these decisions have a standard answer, and following it costs nothing while ignoring it creates work later.

WhereConventionWhy
URLsLower case, hyphen separatedHyphens read as word breaks
CSS classeskebab-caseMatches the language's own style
JavaScriptcamelCaseUniversal in the ecosystem
Pythonsnake_caseSpecified in PEP 8
ConstantsUPPER_SNAKE_CASESignals do not reassign
FilenamesLower case, no spacesSurvives every operating system

The filename rule is the one people learn the hard way. Spaces need quoting in a shell, capitals matter on Linux and do not on macOS, and a file that works on one machine and not another is a genuinely miserable thing to debug. Lower case with hyphens works everywhere.

URL slugs deserve the same care because they are permanent in a way most things are not. Every link anyone makes to a page points at its slug, so changing one later means either breaking those links or maintaining a redirect indefinitely.

Where a project already has a convention, follow it even if you prefer another. Consistency inside a codebase is worth more than any individual rule, and a file that follows a different style is a small friction on every future read.

Your text stays on your device

Everything here runs inside the page. Nothing you type or paste is transmitted, stored or logged, and there is no account, no analytics on the content and no server that ever sees it.

That matters more for text tools than it looks. The things people run through them are unpublished articles, coursework, client proposals, cover letters, contract wording and internal documents. Every one of those pasted into a hosted tool becomes a copy on somebody else's machine, kept for a period nobody states.

Because the work happens locally it is also instant. There is no button to press and no round trip to wait for: the result updates as you type, on text of any length, and it keeps working with the connection switched off.

Nothing is saved between visits either. Close the tab and the text is gone, which is the correct behaviour for a tool you reached for once to fix one thing.

No limits, and no account

There is no cap on how much text you can run through this, no daily quota and no sign up wall at the point where it becomes useful. The Case Converter tool costs us nothing to provide because it runs on your device rather than ours, so there is nothing to meter.

There is also nothing to install. It is one page of HTML, one stylesheet and one script, which together come to a fraction of the weight of a single photograph. It loads in well under a second on a phone connection and works immediately.

Why we built it this way

A tool this simple should not require an account, an upload or an advert covering the result. The work is a few milliseconds of arithmetic on text you already have, and there is no honest reason for it to involve a server at all.

The whole site is built on the same rule: if the work can be done in the browser, it is done in the browser. Over a hundred tools work that way, and the handful that genuinely cannot are the ones we have not built.

It also means the tool keeps working when we are not paying attention to it. There is no service to go down, no API key to expire and no rate limit to hit at the moment you need it most. The page you loaded is the whole program, and it will behave the same way in five years as it does today.

FAQ

Case Converter

The questions people ask most about this tool.

Title case capitalises the first letter of every word. Sentence case capitalises only the first word and any proper nouns, exactly as a normal sentence is written.

Yes. It lowercases everything first and then capitalises after each full stop, so a shouted paragraph comes back readable.

It flips the case of every character. It is mainly useful for undoing text typed with caps lock on by mistake.

No. Recognising names requires understanding the text, so London becomes london. Correct those by hand afterwards.

Completely, with no account, no quota and no paid tier. It runs on your own device, so there is nothing for us to meter and nothing to charge for.

No. Everything happens inside this page, in memory on your machine. Nothing is transmitted, stored or logged, and you can confirm it by watching your browser's network panel while you type.

Yes. Once the page has loaded it never needs the network again, so you can disconnect and carry on working.

None that we impose. The practical limit is your device's memory, which on a modern machine is a very large amount of text.

Yes. The panes stack on a narrow screen and the controls stay reachable. Autocorrect is switched off in the input, so nothing is silently changed as you type.

Yes, freely and with no attribution required. What you paste is yours and so is what comes out.

Yes. A capitalize my title, a title case converter and a title capitalizer all describe this page. The names differ because people describe the same job differently; the job itself does not change.

Need a different conversion?

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