snake_case vs camelCase — when to use which?

Convention by language. Python, Ruby, Rust, PHP, and Elixir use snake_case for variables and function names. JavaScript, Java, C#, Swift, Kotlin, and TypeScript use camelCase. SQL column names trend snake_case across most database conventions. JSON sent over HTTP is mostly camelCase now but plenty of older APIs (especially Rails-derived) are snake_case. If you're converting a payload from one stack to another (Django backend to React frontend, for instance), this tool exists precisely for that round-trip.

kebab-case — is that just for URLs?

Mostly URLs and CSS class names. Google's SEO docs say to use hyphens (kebab) as word separators in URLs because Google treats hyphens as word breaks but underscores as joiners. So "my-blog-post" indexes as three words; "my_blog_post" indexes as one. CSS by convention uses kebab too (properties like "background-color," class names like ".btn-primary"). File names on case-insensitive filesystems (macOS HFS+, Windows NTFS by default) also benefit from kebab because mixed case can cause surprising bugs when the same filename exists in two different cases across collaborators.

Does it work on non-English text?

UPPERCASE, lowercase, and Sentence case work on any Unicode text — that's JavaScript's native case-folding, which handles Greek, Cyrillic, Turkish, German Eszett, and so on correctly. Title Case capitalizes the first character of every space-separated token, which works for most space-separated scripts. camelCase and snake_case strip non-ASCII alphanumeric characters, so accented Latin characters get dropped. Use the slug generator for transliteration before converting if you need to preserve meaning across that step.

No practical cap. The conversion is O(n) in the text length, so even a multi-megabyte document converts in milliseconds. Browser textarea performance is usually the first thing to break past about a million characters, but the case conversion itself stays fast indefinitely.

Why aLtErNaTiNg case?

Because someone always asks for it. It's the "SpOnGeBoB MoCkInG" meme case, used for sarcastic emphasis in chats and social media. Has zero legitimate use in code or prose, but the JavaScript to add it was three lines and now it's there.

Text Case Converter Online Free

Convert text between twelve cases at once — UPPERCASE, Title Case, camelCase, snake_case, kebab-case, PascalCase, dot.case, and a few odd ones. See every result, click to copy.

In your browser—your files never leave your device.

Learn more

Conversions run in your browser. Nothing is sent anywhere.

Case-conversion tools usually let you pick one output, hit Convert, then start over for the next case. This one shows every conversion at once. Type a phrase, see it rendered eight ways immediately, click whichever you need. It's built for developers renaming variables across language conventions (camelCase in JavaScript, snake_case in Python, kebab-case in CSS) and for writers fighting Title Case rules at the end of a draft. The conversions run in JavaScript on your device. No upload, no length cap, no signup, no "free for the first 500 characters" trick. Open the page, paste, click, done.

How to text case converter online free

Paste your text

A variable name, a heading, a paragraph, an entire chapter. Any length, any language. The same converter handles them all.
Read every result at once

Twelve conversions render live in a list below: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, CONSTANT_CASE, kebab-case, dot.case, plus aLtErNaTiNg for the meme.
Click to copy

Each row is a click target. The conversion lands on your clipboard the moment you click it, with a small "Copied!" confirmation that fades after about a second.
Paste where you needed it

Into the code editor, the CMS field, the URL bar, the chat, the email subject line. Done in under five seconds from paste to paste.

Features

Twelve conversions, all at once

UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, CONSTANT_CASE, kebab-case, dot.case, and aLtErNaTiNg. The set that covers actual code conventions plus the prose cases writers need, with the silly one thrown in because someone always asks. No "Convert" button to click — every output renders the instant you have text in the input.

Instant in-browser conversion

Conversion happens in JavaScript the moment you type. No round-trip to a server, no spinner, no rate limit. Even a multi-megabyte paste converts immediately because the math is dirt cheap — each conversion is one regex sweep over the input string. I tested it with a 200,000-word manuscript and the conversion was instant on a five-year-old MacBook.

Built for code, friendly for prose

camelCase and snake_case strip punctuation and merge spaces, which is what you want for identifiers. kebab-case does the same with hyphens. Title Case respects multi-word phrases. Sentence case capitalizes after periods, exclamation marks, and question marks the way English actually works. Most online tools just uppercase the first letter and call it done.

No length cap, no rate limit

A single word or an entire novel. The same converter, same instant response, no upload step. There's no "free up to N characters, premium past that" — the math is O(n) and runs locally, so there's no infrastructure cost that would justify a paywall.

Privacy & security

Twelve case conversions, all of them simple string transformations that run in JavaScript when you type. UPPERCASE is String.toUpperCase(); camelCase, snake_case, kebab-case, and PascalCase are tokenize-then-reassemble operations on the same input string. Output blocks update in your tab as you type. If the input is a variable name with sensitive context — an internal API parameter, a column name from a private database — none of that text reaches our server.

Frequently asked questions

Is it free?

Yes. No limit, no signup, no ads inside the tool. The whole thing is roughly 80 lines of TypeScript — there's no honest business case for charging. If a competitor is gating case conversion behind a "premium" tier, they're renting you nothing.

Privacy?

Conversions happen with JavaScript in your browser. Nothing is uploaded. You can disable the network in your dev tools, paste a paragraph, click any of the cases, and watch the network panel stay silent. The text never crosses a network; it doesn't even cross between iframe boundaries inside the page.

Which cases do you support?

UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, CONSTANT_CASE (an alias of SCREAMING_SNAKE_CASE — listed so people searching either term find a direct hit), kebab-case, dot.case, and aLtErNaTiNg. The set covers JavaScript/TypeScript/Java/C# (camelCase, PascalCase), Python/Ruby/Rust (snake_case), C/C++ macros (SCREAMING_SNAKE_CASE), language-level constants (CONSTANT_CASE), URLs/CSS classes (kebab-case), namespaced identifiers (dot.case), plus prose and the meme.

Title Case rules — which style guide?

An AP/Chicago hybrid that does what most editors expect rather than the lazy "uppercase every word" behaviour most online tools ship. Articles (a, an, the), coordinating conjunctions (and, but, or, nor, so, yet, for), and short prepositions (as, at, by, in, of, off, on, per, to, up, via) stay lowercase, but the very first and very last words are always capitalised — and capitalisation restarts after a clause-ending punctuation mark (period, exclamation mark, question mark, colon). So "the quick brown fox" becomes "The Quick Brown Fox" (first word capitalised), "a tale of two cities" becomes "A Tale of Two Cities" (article kept lowercase mid-title), and "alice in wonderland: a journey" becomes "Alice in Wonderland: A Journey" (article capitalised after the colon). If you're writing for the New York Times, run your title through their own house style guide; for everyone else, this matches the rules every other style guide agrees on.

How does Sentence case know where sentences start?

It lowercases everything, then capitalizes the first character of the input plus any character that follows a period, exclamation mark, or question mark plus whitespace. That handles the cases you actually paste in. Abbreviations like "Dr." and "U.S.A." will trigger a false capitalization after the period, which is a known quirk of any rule-based sentence-case algorithm. Proper handling needs a dictionary of abbreviations, which would balloon the tool's code size for a marginal correctness gain.

About this tool