Case Converter
Need to quickly rewrite a headline in ALL CAPS, or tame the Caps Lock that got left on halfway through an email? Or maybe you’re wondering what a variable you’d normally write with underscores in Python should look like in JavaScript? Our Case Converter handles both — one click rewrites your text into every common everyday and programming format at once.
Our tool is a Swiss Army knife for text formatting. Just type your text once (in any format), and we’ll instantly rewrite it into the nine other variants.
Quick uppercase/lowercase conversion (no coding required)
The most common use is also the simplest: you just need text all in caps, all in lowercase, or neatly formatted for a heading.
- UPPERCASE: Ideal for headings, logos, alerts, or forms that require capital letters (e.g. an address on an envelope).
- lowercase: Great for cleaning up data — say, when someone sends you an email address or username typed in a random mix of CapItaLS and you need to normalize it.
- Title Case: Every Word Starts With A Capital Letter — used for article headlines, product names, or presentations in the Anglo-American style.
- Sentence case: Only the first letter of the sentence is capitalized, the rest is lowercase — exactly how a standard English sentence is written.
Just paste your text into the box, pick the format you need, and hit Copy. No manually undoing Caps Lock or retyping letter by letter.
Quick overview: which case to use in programming?
If you code and aren’t sure which naming convention applies where, here’s a cheat sheet:
🐪 camelCase (Camel Notation)
Starts with a lowercase letter, and each subsequent word begins with an uppercase letter. No spaces.
- Where it’s used: JavaScript, Java, Swift, Kotlin, Go.
- Examples:
myVariableName,getElementById,iPhone.
🐍 snake_case (Snake Notation)
All letters are lowercase and separated by underscores.
- Where it’s used: Python, Rust, PHP, SQL databases, file names.
- Examples:
user_id,first_name,def my_function().
🍢 kebab-case (Kebab Notation)
Lowercase letters separated by hyphens. Looks like meat on a skewer.
- Where it’s used: CSS classes, HTML attributes, URLs (slugs), Kubernetes.
- Examples:
font-size,my-cool-article,<div id="main-content">.
📐 PascalCase (UpperCamelCase)
Similar to camelCase, but the first letter is uppercase.
- Where it’s used: Class names in most languages (JS, Python, PHP), C# (methods and variables), React components.
- Examples:
UserProfile,AppController,ReactComponent.
📢 CONSTANT_CASE (Screaming Snake Case)
Uppercase letters separated by underscores. It screams at you that this value should not change.
- Where it’s used: Constants, ENV variables, global configurations.
- Examples:
MAX_RETRIES,API_KEY,DB_PASSWORD.
How does our converter work?
Our tool is “smart.” That means it doesn’t just blindly replace spaces or change letters one by one.
- Word detection: The algorithm recognizes individual words, whether they’re separated by spaces (
hello world), underscores (hello_world), hyphens (hello-world), or a shift to a capital letter (helloWorld). - Normalization: Everything is converted to a base form, regardless of how the text was originally written.
- Generation: It assembles all the variants at once — from plain upper/lowercase to the full set of programming conventions.
This is handy, for example, when refactoring code and you need to turn an old PHP variable ($user_id) into modern JavaScript (userId) or build a CSS class (user-id) from a database column name. But it works just as well for everyday writing, whenever you need to quickly normalize letter casing without opening Word or Excel.
FAQ: Frequently Asked Questions
How can I convert text to uppercase online without retyping it by hand?
Paste your text into the box above and choose the UPPERCASE format. The tool instantly converts the whole text to capital letters — it also works with accented characters — and you can copy the result right away.What is "Hungarian notation"?
This is an older naming convention (common in C/C++ in the 90s) where a variable name starts with an abbreviation of its data type. For example,strName (string) or iCount (integer). It's not widely used in modern languages today because IDEs automatically show us the types.
Can I use kebab-case in JavaScript?
Not directly as a variable name, because the hyphen- acts as a subtraction operator in JS. var my-variable would mean "my minus variable." Kebab-case is only used in JS as keys in objects, if they are in quotes: { "content-type": "json" }.
Which case should I use for JSON?
The JSON standard doesn't specify a case, but Google and most REST APIs use camelCase (e.g.,createdAt). Conversely, some older APIs and Python backends return snake_case (e.g., created_at). It's important to be consistent.