Case Converter

What is a case converter and who needs one?

A case converter is a text transformation tool that changes the capitalisation pattern of a string from one style to another in a single click. Writers use it to fix accidentally capitalised text, apply consistent heading styles, or reformat copied content that arrived in the wrong case. Developers reach for it when transforming human-readable labels into programming identifiers — converting "user full name" into userFullName (camelCase), user_full_name (snake_case) or user-full-name (kebab-case) without manual retyping. This tool supports twelve distinct case formats and converts in real time. Once your text is the right case, verify its length against platform limits with our Character Counter, or check its total word count with our Word Counter.

What are all twelve case formats and when is each used?

• UPPER CASE — All letters capitalised. Used for acronyms, legal emphasis, warning labels and environment variable names.
• lower case — All letters lowercase. Common in URL paths, email addresses and systems where uppercase is reserved for emphasis.
• Title Case — First letter of every word capitalised. Standard for article headings, book titles and proper nouns.
• Sentence case — Capitalises the first word of each sentence and the standalone pronoun "I" (including contractions like "I'm" or "I've"), without disturbing any capitalisation you've already typed elsewhere — so names, places and acronyms you wrote correctly stay correct. The natural style for body text, UI labels and captions.
• tOGGLE cASE — Each letter's case is flipped. Used for social-media humour or mocking quotation style.
• camelCase — No spaces, each word after the first begins with a capital. The standard identifier style in JavaScript, Java, Swift and Kotlin.
• PascalCase — Like camelCase but the first word is also capitalised. Standard for class names, component names and TypeScript interfaces.
• snake_case — Words separated by underscores, all lowercase. The default for variables in Python and Ruby, and for column names in SQL databases.
• kebab-case — Words separated by hyphens, all lowercase. Standard for CSS class names, HTML element IDs and clean URL slugs. Combine with our Text to Slug Generator for complete URL formatting.
• CONSTANT_CASE — All uppercase with underscore separators. The universal standard for named constants and environment variables across all languages.
• dot.case — Words separated by full stops. Used in configuration file keys, Java package names and structured logging namespaces.
• aLtErNaTiNg — Letters alternate between lower and uppercase. A purely stylistic format popular in ironic internet culture.

Does Sentence case capitalise proper nouns like names and places?

Sentence case capitalises the first word of each sentence, the pronoun "I" (including contractions like "I'm" and "I'll"), and a curated list of common names, countries, continents and major cities — even when you type them in lowercase. For example, "john is from canada, he visited europe last year" becomes "John is from Canada, he visited Europe last year". It also force-uppercases a set of common acronyms — "usa", "uk", "eu", "hr", "ai", "ceo", "seo", "html" and similar all convert correctly regardless of how you typed them.

The name and place list is deliberately curated to avoid words that double as ordinary English vocabulary. Common names like "Will", "May", "Mark", "Hope", "Grace" and "Rose" are intentionally left out, because a tool that capitalises these on sight would turn "i hope you can mark the date" into "I Hope you can Mark the date", which is wrong — and countries like "Turkey" and "China" are excluded for the same reason (the bird and the porcelain are far more common in everyday text than the country). Because the list can never be complete — it can't cover every name, town or company in the world — any proper noun outside the list still needs manual capitalisation. The good news is that Sentence case is non-destructive: if you've already capitalised a name the list doesn't recognise, it stays exactly as you typed it. Run the result through our Spell Checker afterwards to catch anything else that needs attention.

Does title case capitalise every single word?

No — Title Case follows the same convention used by AP, Chicago and most editorial style guides: short articles ("a", "an", "the"), coordinating conjunctions ("and", "but", "or", "nor", "so", "yet") and short prepositions ("of", "in", "on", "to", "by", "at", "up", "via" and similar) are lowercased, while every other word — including the first and last word of the title, and the first word after a colon or dash — is capitalised. Verbs are always capitalised regardless of length, so words like "is", "be", "was" and "are" stay capitalised even though they are short; only articles, conjunctions and prepositions are affected. This matches how professional headlines and book titles are formatted. For example, "the lord of the rings" becomes "The Lord of the Rings" — "Lord" and "Rings" are capitalised, "the" stays lowercase except as the first word, and "of" stays lowercase throughout. To check the character length of your formatted title against Google's display limit, use our Character Counter.

Can I use this to convert code variable names between cases?

Yes — that is one of its primary uses. The camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and dot.case formats all strip spaces and non-alphanumeric characters, producing clean programming identifiers from plain text. Paste "get user profile image" and clicking snake_case gives you get_user_profile_image instantly. This is particularly useful when renaming a batch of variables during a refactor, converting database column names to code conventions, or mapping an API response field format to a different codebase's naming standard. After generating your identifiers, use our Word Frequency Counter to spot repeated terms that might indicate redundancy in your naming scheme.

Does this tool work correctly with non-English and accented text?

Uppercase and lowercase conversion uses JavaScript's native toUpperCase() and toLowerCase() methods, which correctly handle extended Latin characters used in most European languages — é becomes É, ü becomes Ü, ñ becomes Ñ and so on. Languages that do not have a case distinction — such as Arabic, Chinese, Japanese and Korean — pass through the uppercase and lowercase conversions unchanged. The programmer-oriented formats (camelCase, snake_case, kebab-case and similar) are designed for ASCII text and treat any non-alphanumeric character as a word separator, which may produce unexpected splits with non-Latin scripts. For those formats, using ASCII input produces the most predictable results.

Can I chain multiple case conversions?

Yes. After converting your text, click the "Use Output as Input" button to load the result back into the input panel, then apply a second conversion on top. This lets you compose transformations — for example, applying sentence case to clean up messy input, then switching to kebab-case to produce a clean URL-ready string. For specialised slug generation with additional options such as removing stop words and handling special characters, our dedicated Text to Slug Generator is the right next step. You can also use Remove Duplicate Lines to tidy the input before converting.

Why does my camelCase or snake_case output look wrong?

The programming case formats treat any sequence of non-alphanumeric characters as a word boundary and rebuild the string accordingly. Edge cases that can cause unexpected splits include: contractions (the apostrophe is non-alphanumeric), hyphenated phrases used as single concepts, repeated punctuation, and leading or trailing symbols. For best results, clean your input before converting — remove trailing punctuation, replace em dashes with spaces, and ensure each logical word is separated by a single space or underscore. The "Use Output as Input" button makes it easy to iteratively clean and reformat. If your text came from a copied list with repeated lines, run it through our Remove Duplicate Lines tool first.

Is there a word or character limit?

No artificial limit is imposed. All processing happens in your browser using JavaScript — documents of tens of thousands of words convert in under a millisecond on any modern device, and nothing is ever sent to a server. The character and word counts shown in the stats bar update live so you always know the size of your input. To check your converted text against social media platform character limits, copy the output and paste it into our Character Counter. To analyse the reading time of your converted content, try our Reading Time Calculator.

Complete Suite of Free Writing Tools on Convixy

• Word Counter — Count words, characters, sentences and paragraphs with reading time and keyword density in real time.
• Character Counter — Real-time character count with live progress bars for Twitter, Instagram, SMS and meta tag limits.
• Text Repeater — Repeat any word, phrase or symbol any number of times with a custom separator.
• Lorem Ipsum Generator — Generate standard or randomised placeholder text at any word count.
• Spell Checker — Highlight misspelled words and get correction suggestions without leaving your browser.
• Word Frequency Counter — Rank every word by occurrence to spot overuse and analyse keyword density.
• Remove Duplicate Lines — Strip repeated lines from any list or block of text in one click.
• Text to Slug Generator — Convert any heading or phrase into a clean, URL-friendly slug for web pages.
• Reading Time Calculator — Estimate reading and speaking time with adjustable WPM and a full audience breakdown.