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Developer/Case Converter

Case Converter

Convert text between 12 naming conventions. Copy any result with one click.

12 MODES12 formatsOne-click copyLive previewNo signup
Input Text
0 characters · 0 words
UPPERCASE
All letters uppercase
HELLO WORLD
lowercase
All letters lowercase
hello world
Title Case
First letter of each word
Hello World
Sentence case
First letter after period
Hello world. This is a test.
camelCase
JS variable naming
helloWorld
PascalCase
Class / component naming
HelloWorld
snake_case
Python / Ruby variables
hello_world
kebab-case
URL slug / CSS class
hello-world
CONSTANT_CASE
Constants / env vars
HELLO_WORLD
dot.case
Config key naming
hello.world
tOGGLE cASE
Swap upper/lower
hELLO wORLD
aLtErNaTiNg
Alternate lower/upper
hElLo WoRlD
Data Source & Legal Disclaimer
Effective: 2026
Sources: Browser-side processing (no external API)

This tool runs 100% in your browser. All computation happens locally on your device — your input is never uploaded to any server. Results are for reference only.

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Case conversion is a pure text transform in your browser — no bytes are sent or received.

Request count is measured live from your browser's performance log — it cannot be faked. External resources were loaded — see the data-source note below.

How naming conventions differ — illustrated

Every convention answers one question differently: how do you join words without spaces? The separator character (or lack of one) and the capitalization rule are the entire difference between user_id_count and userIdCount.

Three words → five conventions
useridcount3 words, no spacescamelCaseuserIdCountno separatorsnake_caseuser_id_count_ separatorkebab-caseuser-id-count- separatorCONSTANT_CASEUSER_ID_COUNT_ + uppercasePascalCaseUserIdCountno sep + caps

Tools and languages each standardize on a convention for consistency — Python uses snake_case for variables, JS uses camelCase, URLs use kebab-case, and environment variables use CONSTANT_CASE.

Picking the right one

The same words 'page views this month' become completely different identifiers. Context decides which is correct.

  1. Python variable:page_views_this_month — snake_case for readability
  2. JS function:pageViewsThisMonth — camelCase in JavaScript
  3. React component:PageViewsThisMonth — PascalCase for components
  4. URL slug:page-views-this-month — kebab-case in a web path
12 naming conventions at a glance12
ConventionExampleTypical use
UPPER CASEUPPER CASEEmphasis / shouting
lower caselower casePlain text
Title CaseTitle CaseHeadings
Sentence caseSentence caseProse
camelCasecamelCaseJS variables
PascalCasePascalCaseClasses / components
snake_casesnake_casePython / DB columns
kebab-casekebab-caseURLs / file names
CONSTANT_CASECONSTANT_CASEConstants
dot.notationdot.notationConfig keys
tOGGLE cASEtOGGLE cASEFixing accidental caps lock
aLTERNATINGaLtErNaTiNgMeme / sarcastic text
↩ Back to converter

To convert case: paste your text — the tool instantly converts between UPPERCASE, lowercase, Title Case, Sentence case, and other formats with one click.

FreeToolHub Case Converter is a free browser-based tool that converts text between uppercase, lowercase, title case, and sentence case, no signup.

About this tool

What is this tool?

Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, kebab-case and more. Instant, free, 100% in-browser, no signup.

12 formatsOne-click copyLive previewNo signup

What Is the Case Converter?

This tool converts text between every casing convention programming and publishing use: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE. Paste once, click the target format, and copy — with smart handling for text containing punctuation, digits, and hyphens that naive converters mangle. It also capitalizes sentences properly, fixes ALL-CAPS pastes into readable case, and handles the acronym edge cases like JSON and API inside camelCase conversions where correctness actually matters.

Who Should Use This Tool?

Developers convert between naming conventions when moving data across systems — JSON fields to constants, database columns to variables — and when generating test fixtures. Writers toggle headline styles for different publications' style guides. Marketers produce ad copy in the exact casing each platform's policy expects. Students reformat titles and headings for papers. Anyone retyping a heading to match a convention realizes in seconds that this tool already did it correctly, including the edge cases.

How Does It Work?

(1) Paste your text — single words, headlines, or entire paragraphs. (2) Click a target case: the four display cases (upper, lower, title, sentence) and five code cases (camel, Pascal, snake, kebab, constant) each apply consistent rules. (3) Word boundaries are detected from spaces, hyphens, underscores, and camelCase humps, so mixed-format input normalizes cleanly. (4) Copy the result. Conversion is instant, local, and unlimited; batch pastes of many lines convert in one pass.

Which Case Does Each Convention Use?

The code conventions encode ownership and kind: camelCase (userAccountBalance) for JavaScript variables and function names; PascalCase (UserProfile) for classes, components, and types; snake_case (created_at) for Python, Ruby, and SQL columns; kebab-case (nav-menu-item) for CSS classes, URLs, and file names where hyphens win for SEO and readability; CONSTANT_CASE (MAX_RETRIES) for environment variables and enum values. Publishing conventions differ subtly: Title Case capitalizes principal words (The Art of War) per style guides with small-word exceptions; Sentence case capitalizes only first words and proper nouns (The art of war) and has become the default for web headlines — modern style guides including major platforms now favor it for readability. Acronym rules trip manual conversion most: preserve JSON, API, and URL as units in code cases, and decide house style for title case — this tool's smart mode keeps known acronyms intact instead of shattering them into Json.

Frequently Asked Questions

Which text cases does it support?

UPPERCASE (all caps), lowercase, Title Case (capitalize first letter of each word), camelCase (first word lowercase, subsequent words capitalized, no spaces), PascalCase (all words capitalized, no spaces), snake_case (words separated by underscores), kebab-case (words separated by hyphens), SENTENCE CASE (first word capitalized only), and CONSTANT_CASE (uppercase with underscores). Real-time preview as you type.

Can it handle multi-line text and code snippets?

Yes. Paste any text—paragraphs, code blocks, variable names, or lists. The converter preserves line breaks and applies the selected case transformation to each line independently. This is useful for converting variable naming conventions (e.g., camelCase to snake_case) when refactoring code between languages (JavaScript to Python).

Other names for this tool

This tool is also known by these tasks — each link opens the same tool with a focused guide:

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