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Text & Writing Tools

Case Converter

See every case format at once — from Title Case to snake_case.

Also known as: Text case changer, Capitalization converter, Naming convention converter

100% FreeNo Signup Required14 Formats At OnceSmart Title Case
100% local — nothing you enter here ever leaves this browser tab
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Step by step

How it works

  1. 1Type or paste your text into the box.
  2. 2All 14 case formats update instantly below — no need to pick a target format first.
  3. 3Toggle "Smart Title Case" on or off depending on whether you want AP-style capitalization or every word capitalized.
  4. 4Click the copy button next to whichever format you need.
Why OTL

Why use Case Converter

See everything at once

No dropdown, no committing to a format upfront — all 14 case styles are visible and ready to copy the moment you type.

Style-aware Title Case

Smart Title Case correctly lowercases connector words like "a", "of", and "the" per AP-style convention, not just capitalizing every single word.

Understands existing formatting

Paste in camelCase or snake_case text and it's correctly split back into words before converting — not mangled.

Covers both prose and code

From Sentence case for writing to snake_case and kebab-case for code and URLs, one tool handles both worlds.

One-click copy per format

Every result has its own copy button, so grabbing exactly the format you need takes one click, not a select-and-copy.

Nothing uploaded, ever

All conversions run locally in your browser — your text is never sent anywhere to be transformed.

Real-world use

Who uses Case Converter

Renaming a variable across languages

Convert a variable name into camelCase for JavaScript, snake_case for Python, and CONSTANT_CASE for an environment variable, all at once.

Fixing a Caps Lock accident

Recover text typed with Caps Lock on by converting it straight to Sentence case or Title Case.

Formatting a page or article title

Get a properly styled Title Case heading that correctly lowercases small connector words.

Building a URL slug or CSS class

Grab the kebab-case output directly for a URL path segment or CSS class name.

Preparing a spreadsheet column header

Convert a natural-language label into snake_case for a database column or API field name.

Standardizing pasted text

Normalize inconsistent capitalization from a pasted email or document into clean Sentence case.

Deep dive

About Case Converter

Most case converters make you commit to a target format before you see anything — pick "UPPERCASE" from a dropdown, click convert, read the result, then go back and try "Title Case" instead if that's not what you needed after all. It's a small friction, but it adds up if you're not sure which format fits until you see it, or if you need the same text in three different formats for three different places (a page heading, a URL slug, and a variable name, say).

This tool skips that back-and-forth by converting into all fourteen formats at once, live, as you type. Six of them — UPPERCASE, lowercase, Sentence case, Title Case, aLtErNaTiNg CaSe, and InVeRsE cAsE — preserve your original punctuation and spacing exactly, only changing letter casing. The other eight — camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, Train-Case, and path/case — are built for code and URLs, where spaces aren't allowed at all, so the tool intelligently splits your text into words first (correctly detecting word boundaries even in an existing camelCase or snake_case input) before rejoining them in the target format.

Title Case gets particular care, because doing it well is genuinely more subtle than capitalizing every word. Style guides like AP and Chicago agree that short connector words — "a", "the", "and", "of", "in", and similar — should stay lowercase in a title unless they're the first or last word, which is why "The Lord of the Rings" isn't written as "The Lord Of The Rings". This tool's Smart Title Case toggle applies that convention automatically; turn it off if you specifically want every word capitalized instead.

For developers, this doubles as a fast way to rename something across naming conventions — paste a variable or function name and instantly see it as camelCase for JavaScript, snake_case for Python, kebab-case for a CSS class or URL, and CONSTANT_CASE for an environment variable, without writing a regex or opening a separate script. As with every tool here, all fourteen conversions run locally in your browser the instant you type.

Compare

Case Converter vs. other options

How Open Tools Library compares to desktop software and other online tools.

FeatureOpen Tools LibraryDesktop softwareOther online tools
PriceFree, unlimitedFree (manual, in a text editor)Often free
Formats shown at once14, all liveOne at a time, manualUsually 1 selected from a dropdown
Smart Title CaseBuilt in, toggleableNot availableRare
Programming case formats8 formats includedNot availableSometimes, limited set
Data privacyNever leaves your deviceStays localOften sent to a server
SpeedInstant, live as you typeManualRequires a click per format
Pro tips

Pro tips

  • Turn off Smart Title Case if you specifically want every single word capitalized, including small words like "a" and "the".
  • Programming-style formats (camelCase, snake_case, etc.) strip punctuation, since none of those formats support it — use the prose formats if you need to keep it.
  • Pasting text that's already in camelCase or snake_case works correctly — the tool detects existing word boundaries before converting to a new format.
  • aLtErNaTiNg CaSe and InVeRsE cAsE are mostly for fun or mockery text ("sarcasm case") — they're included because people genuinely search for them.
  • For code, double check whether your language or framework prefers camelCase, snake_case, or kebab-case before picking one — conventions vary (JavaScript typically uses camelCase, Python typically uses snake_case, CSS and URLs typically use kebab-case).
Under the hood

Technical specs

Case formats generated
14, simultaneously
Title Case style
AP-style smart mode, toggleable
Word boundary detection
Handles spaces, camelCase, snake_case, kebab-case input
Text length limit
None enforced
Update speed
Live, on every keystroke
Processing location
100% local, in your browser

Privacy & security

Text run through a case converter is often about to be pasted somewhere else entirely — code, a CMS, an email — so it shouldn't have to pass through a stranger's server first.

All 14 case conversions are computed locally in your browser tab — your text is never transmitted anywhere.

No account or signup is needed for any part of this tool.

Nothing you type is stored or logged — refresh the page and it's gone.

Works the same for a confidential internal document as it does for a public headline.

FAQ

Frequently asked questions

Is my text sent anywhere while converting?

No. All 14 case conversions happen locally in your browser using plain JavaScript — nothing is ever uploaded.

What's the difference between Title Case and Smart Title Case?

With Smart Title Case on, small connector words like "a", "of", and "the" stay lowercase (AP style) unless they start or end the title. With it off, every word is capitalized, including small ones.

Does it work on text with existing camelCase or snake_case formatting?

Yes — the tool detects word boundaries in camelCase, PascalCase, snake_case, kebab-case, and space-separated text before converting, so re-casing already-formatted text works correctly.

What's Train-Case and path/case for?

Train-Case (Like-This) is used in some coding conventions and HTTP headers; path/case is useful for building URL paths or file-system-style paths from plain text.

Is there a text length limit?

No hard limit — longer text just takes a fraction of a second longer to process, entirely on your device.

Can I convert multiple lines or a whole paragraph at once?

Yes — paste in as much text as you like; all 14 formats update for the entire input, not just a single line.

Stuck?

Troubleshooting

My punctuation disappeared in camelCase or snake_case output

This is expected — programming case formats don't support spaces or punctuation, so the tool strips them while splitting your text into words. Use one of the prose formats (UPPERCASE, Title Case, etc.) if you need to keep punctuation.

Title Case isn't capitalizing a word I expected it to

If Smart Title Case is on, common connector words like "a", "of", "in", and "the" stay lowercase unless they're the first or last word, matching AP style. Turn the toggle off to capitalize every word instead.

Converting my snake_case text back to Title Case looks wrong

Check that underscores were correctly treated as word breaks — the tool splits on underscores, hyphens, and camelCase boundaries automatically, so "user_first_name" should become "User First Name".

Numbers in my text aren't being separated as their own word

Numbers stay attached to adjacent letters unless there's already a clear boundary (a space, underscore, hyphen, or a lowercase-to-uppercase transition) — this matches how most case-conversion tools and coding style guides handle numbers.

Ready to use Case Converter?

Free, private, and ready right now — no signup required.

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