Case converter

1. Paste or type your text. Drop anything into the box above — a headline, a paragraph, an email someone wrote entirely in caps, or a variable name. Character, word, and sentence counts update as you type.
2. Pick a case. Click one of the twelve style chips — UPPERCASE, lowercase, Title Case, Sentence case, Capitalized Case, aLtErNaTiNg, InVeRsE, kebab-case, snake_case, camelCase, PascalCase, or CONSTANT_CASE. The output converts immediately; there is no convert button to press.
3. Fine-tune if needed. Title Case offers three rule sets (Simple, AP style, Chicago), and Sentence case has a toggle that preserves ALL-CAPS acronyms like NASA or HTML5 instead of flattening them.
4. Copy or download. Hit Copy to put the converted text on your clipboard, or Download to save it as a .txt file. Switching chips re-converts the same input, so you can compare styles freely.

Because the conversion is plain JavaScript running in your own tab, there are no length limits beyond what your browser can hold, no account, and no daily quota — paste a tweet or an entire chapter.

Here is each of the twelve styles applied to a short example, so you can see at a glance which one you need:

The single most common job for a text case changer is converting uppercase to lowercase: someone sends you a message typed with caps lock on, a legacy system exports names in all caps, or you inherit a spreadsheet where an entire column SHOUTS. Retyping is slow and introduces typos; pasting here and clicking lowercase fixes the whole block in one motion. The reverse direction works exactly the same way when you need all caps for a heading, a coupon code, or a form that demands capital letters.

The less obvious styles earn their place too. InVeRsE flips the case of every individual letter, which rescues text typed while caps lock was accidentally on — “hELLO tHERE” becomes “Hello There” without touching anything else. aLtErNaTiNg produces the mocking “spongebob” meme style beloved on social media. And Capitalized Case simply capitalizes the first letter of every word — a quick fix for name fields and address lines that arrived in the wrong shape.

Title case looks simple until you ask which words shouldn't be capitalized. Style guides disagree, which is why this title case converter lets you choose between three rule sets instead of guessing:

• Simple capitalizes every word, no exceptions. It's the safest choice when you just want a tidy headline and nobody is checking a style manual.
• AP style follows the Associated Press convention used by most newsrooms: articles, coordinating conjunctions, and prepositions of three letters or fewer (a, an, the, and, but, of, to, in…) stay lowercase, while any word of four or more letters is capitalized — including longer prepositions like “With” and “About”.
• Chicago follows The Chicago Manual of Style, the standard for books and academic publishing: articles, coordinating conjunctions, and prepositions stay lowercase regardless of length — so “between” and “through” remain lowercase where AP would capitalize them.

In all three styles the first and last words of each line are always capitalized, which is the one rule every guide agrees on. If you're writing headlines for a specific publication, match their house style; if you're writing for yourself, pick one and stay consistent.

A sentence case converter lowercases everything, then capitalizes the first letter of each sentence. This tool detects sentence boundaries at periods, exclamation marks, question marks, and line breaks, so multi-paragraph text comes out correctly rather than as one endless lowercase block.

The classic failure mode of naive sentence-casing is acronyms: convert “NASA LAUNCHED THE PROBE” carelessly and you get “Nasa launched the probe” — wrong, and embarrassing in published copy. That's why the tool ships with a Preserve ALL-CAPS acronyms toggle, on by default. With it enabled, words that are entirely capitals (two or more letters, digits allowed) pass through untouched: NASA stays NASA, HTML5 stays HTML5, USA stays USA. Turn it off when the source text is entirely uppercase — in that situation every word looks like an acronym, so you'll want the tool to lowercase everything and then re-capitalize sentence starts.

The five developer styles do more than change letters — they rebuild the string. The converter first splits your text into words, breaking on spaces, punctuation, and existing camelCase boundaries, then reassembles them: kebab-case joins lowercase words with hyphens (ideal for URL slugs and CSS classes), snake_case uses underscores (Python, Ruby, SQL columns), camelCase lowercases the first word and capitalizes the rest (JavaScript variables), PascalCase capitalizes every word with no separator (class and React component names), and CONSTANT_CASE shouts with underscores (environment variables and constants).

Because camelCase boundaries are detected, you can convert in any direction: paste getUserProfileURL and kebab-case returns get-user-profile-url. Each line of a multi-line paste is converted independently, so you can transform a whole column of identifiers in one go — handy when renaming database fields or migrating an API's naming convention. For slugs specifically, the dedicated slug generator also strips accents and special characters.

• Zero typos. Retyping a paragraph to fix its case reintroduces the very errors you were cleaning up. A converter transforms only the letter case and leaves every character, space, and line break exactly where it was.
• Instant comparison. Because the chips apply live to the same input, you can flip between AP and Chicago title case, or between kebab and snake, and see the difference immediately.
• Counts included. Character, word, and sentence counts update as you type, so you can check a headline against a length limit without opening a second tool. For per-platform limits, the character counter goes deeper.
• Keyboard-friendly. Every chip and button is reachable with Tab and activated with Enter or Space — no mouse required for the paste → convert → copy loop.

Yes. The conversion is a handful of plain JavaScript string operations executed in this browser tab. Your text is never attached to a network request, never logged, and never stored by this tool — it exists only in your browser's memory while the page is open. That makes it safe for confidential material: internal emails, unpublished drafts, legal text, customer data. It also means the tool keeps working with no internet connection once the page has loaded, and there is no server-side length cap — the only limit is your own device.

• Writers & editors normalizing headlines to AP or Chicago title case and fixing copy that arrived in all caps.
• Marketers matching the casing conventions of each platform — sentence case for email subject lines, title case for blog headlines, lowercase for hashtags.
• Developers converting identifiers between camelCase, snake_case, kebab-case, and CONSTANT_CASE while refactoring or writing config files.
• Students & researchers formatting paper titles and reference lists to a required citation style.
• Support & operations teams cleaning up CRM records, name fields, and exports where the casing is inconsistent.

If your text also needs stray line breaks removed or duplicate lines deduped before converting, run it through the text cleaner first — and for decorative Unicode styles rather than plain casing, try the fancy text generator.