Different languages, file systems, and conventions use different ways of joining words together. JavaScript variables are usually camelCase. Python variables are usually snake_case. CSS classes are kebab case. URLs are kebab case too. Database column names are snake_case in most teams. Class names in most object oriented languages are PascalCase. Constants are SCREAMING_SNAKE_CASE.
When you copy a name from one context to another, you usually need to convert it. A case converter does this in one click. This article explains the most common case styles, when each one is used, and how to use the DevHexLab Case Converter to switch between them instantly.
The Common Case Styles
There is a fixed vocabulary of case styles that show up across programming. Knowing them by name makes communication easier.
camelCase
In camelCase, the first word is lowercase and every subsequent word starts with a capital letter, with no separators. So "user name" becomes userName, and "first time login count" becomes firstTimeLoginCount. JavaScript, TypeScript, Java, Swift, and many other languages use camelCase for variables and methods.
PascalCase
PascalCase is like camelCase but the first letter is also capitalised. So "user name" becomes UserName, and "first time login count" becomes FirstTimeLoginCount. PascalCase is conventional for class names, type names, and React component names.
snake_case
In snake_case, words are lowercase and joined by underscores. So "user name" becomes user_name. Python, Ruby, Rust, and most SQL databases use snake_case for variables, function names, and column names.
SCREAMING_SNAKE_CASE
SCREAMING_SNAKE_CASE (also called UPPER_SNAKE_CASE or constant case) uses uppercase letters with underscore separators. So "max retry count" becomes MAX_RETRY_COUNT. It is used for constants in most languages, including JavaScript, Python, Java, and C.
kebab case
In kebab case, words are lowercase and joined by hyphens. So "user name" becomes user-name. URLs, CSS class names, HTML attribute names, and command line flags use kebab case.
UPPERCASE and lowercase
These are not really case styles in the structured sense but they are common operations. UPPERCASE converts every letter to its uppercase form. lowercase converts every letter to its lowercase form.
Title Case
In Title Case, each major word starts with a capital letter. "the quick brown fox" becomes "The Quick Brown Fox". Book titles, headings, and many proper nouns use Title Case. Some style guides keep short words like "of", "the", and "and" lowercase unless they are the first word.
Sentence case
In Sentence case, only the first letter of the first word is capitalised, and the rest of the sentence is lowercase except for proper nouns. "THE QUICK BROWN FOX" becomes "The quick brown fox". Email subjects and short messages often use Sentence case.
When Each Case Style Is Right
Picking the right case is rarely a creative decision. It is dictated by your language, framework, and team conventions.
JavaScript and TypeScript: camelCase for variables and functions, PascalCase for classes and types, SCREAMING_SNAKE_CASE for constants.
Python: snake_case for variables and functions, PascalCase for classes, SCREAMING_SNAKE_CASE for constants.
CSS: kebab case for class names and custom property names.
HTML: kebab case for attribute names.
URLs: kebab case for path segments and parameters.
SQL: snake_case for column and table names is the most common convention, though some teams use PascalCase for tables.
Filename conventions: kebab case is most common for web assets and JavaScript modules. snake_case is more common in Python projects.
Match the surrounding code. If everything else in the file is camelCase, your new variable should be camelCase. Style consistency matters more than personal preference.
How to Use the DevHexLab Case Converter
Open the Case Converter on DevHexLab. Paste any text into the input area. The text can be a single phrase, a list of names on separate lines, or a code snippet.
Pick the target case from the available options. The output appears below in the selected case. Try several styles to compare them, then click Copy to grab the version you want.
The converter understands input in any case style. You can paste camelCase and convert to snake_case. You can paste a phrase with spaces and convert to PascalCase. The tool detects word boundaries from spaces, capital letters, hyphens, and underscores.
Everything runs in your browser. Nothing is sent to a server.
Practical Examples
Renaming a variable for a different language
You have a Python variable called user_full_name. You need to use it in a JavaScript file. Paste user_full_name into the converter, select camelCase, and get userFullName.
Generating a CSS class name from a heading
You have a heading "Top Selling Products" and need a CSS class for the section. Paste it into the converter, select kebab case, and get top-selling-products.
Creating a constant from a config key
You have a config key called maxRetryCount and need to expose it as a constant. Paste it into the converter, select SCREAMING_SNAKE_CASE, and get MAX_RETRY_COUNT.
Normalizing a CSV column header
You have a CSV with column headers like "First Name" and "Phone Number". Paste them into the converter, select snake_case, and get first_name and phone_number for use in a database import.
Tips for Working with Case Conversions
Pay attention to acronyms
How should "userID" be converted to snake_case? Is it user_id or user_i_d? Most conventions treat consecutive capitals as a single word, so user_id is right. The DevHexLab converter handles common acronyms correctly.
Be careful with numbers
How should "user2name" be converted to camelCase? Most tools treat the number as part of the word, so it stays user2name. If you want user2Name with the next part capitalised, you may need to manually edit the result.
Multi line input is fine
If you have a list of names to convert (like a list of database column names), paste them with one name per line. The converter processes each line independently and preserves the line structure.
Save your team's conventions
If your team has decided on a specific casing rule (such as "always camelCase for new variables"), document it. Style consistency is a small thing that compounds across a codebase.
Frequently Asked Questions
Why are there so many case styles?
History. Different programming language designers in different decades picked different conventions, and those conventions stuck. JavaScript inherited camelCase from Java. Python's creator preferred snake_case. CSS adopted kebab case to work with HTML conventions.
Does the case style affect performance?
No. Once compiled or interpreted, code with different casing runs identically. Casing is purely a readability and convention choice.
Is one case style objectively better?
No. Different styles have different strengths. snake_case is easier to read for long names. camelCase is shorter. kebab case fits URLs but is not allowed in many programming languages as an identifier. Pick what fits your language and team.
Can I convert mixed case input?
Yes. The DevHexLab Case Converter detects word boundaries regardless of the input case. You can paste a mix of camelCase, snake_case, and plain words, and the converter will normalise everything into the target style.
Convert Without Retyping
Case conversion is one of the most boring and most repeated micro tasks in software development. Use a tool. Open the DevHexLab Case Converter, paste your text, pick the target style, and copy the result. Spend your typing on the work that actually changes the program.