文本大小写转换器

What the text case converter does

This tool rewrites whatever you paste into a different letter-casing or naming convention with a single click. Type or paste your text, then choose the style you want: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, or CONSTANT_CASE. It is the utility you reach for when the shape of the text is wrong rather than the words: fixing a heading someone typed IN ALL CAPS, tidying a sentence pasted in lowercase, normalising a column of messy CSV headers, or — most commonly for developers — renaming an identifier from one language’s convention to another’s without retyping it letter by letter.

Simple cases versus word-aware cases

The first four options are pure letter transforms. UPPER and lower map every character to one case; Title Case capitalises the first letter of every word; and Sentence case lowercases everything and then capitalises the first letter after each sentence-ending ., ! or ?. The programmer-oriented styles are smarter, because they first have to work out where the words are. The converter splits your input on spaces, underscores and hyphens, and — crucially — on the boundary inside a run like myXMLParser where a lowercase letter meets an uppercase one. That means it can take input already in one convention and cleanly re-case it into another. From those detected words it builds the target style: camelCase joins them with the first word lowercased and each later word capitalised; PascalCase capitalises every word; snake_case and kebab-case lowercase and join with _ or -; and CONSTANT_CASE uppercases and joins with underscores.

Concrete conversions

• user profile id becomes userProfileId (camel), UserProfileId (Pascal), user_profile_id (snake), user-profile-id (kebab), or USER_PROFILE_ID (constant).
• Snake-cased Python like max_retry_count converts straight to maxRetryCount for JavaScript, or to MaxRetryCount for a C# type name.
• A CSS class such as primary-nav-item flips to a JSON key primaryNavItem and back again.
• An environment variable DATABASE_URL becomes a readable label database url or Title Case Database Url.

This makes it a quick bridge between ecosystems: Python and Ruby favour snake_case, JavaScript and JSON tend to camelCase, class and type names use PascalCase, CSS and URLs lean on kebab-case, and configuration constants use CONSTANT_CASE. If you are lining up field names between an API and a client, our developer documentation shows which convention our request and response payloads use, so you can convert your models to match in one step.

Gotchas worth knowing

A couple of things are worth keeping in mind. Title Case here capitalises every word, so it will also capitalise small words like “of” and “the” that a strict style guide leaves lowercase, and it does not know your acronyms — NASA put through Sentence case comes out Nasa, so proper nouns and initialisms may need a manual touch-up. The programmer styles also strip anything that is not a letter or digit as a separator, so punctuation inside a phrase is discarded rather than preserved. And because casing is Unicode-aware but locale-neutral, edge cases like the Turkish dotless “ı” follow the default rules rather than a language-specific one.

Everything stays in your browser

The conversion happens entirely on your device in JavaScript. Whatever you paste — a block of source code, a customer list, an internal document heading — is transformed locally and is never uploaded, stored, or logged. Nothing about your text reaches a server, which means you can safely run even confidential names and identifiers through it. Close the tab and the text is gone; there is no history kept anywhere.