Constant Case Converter
The Constant Case Converter turns any text into uppercase letters separated by underscores, known as CONSTANT_CASE or SCREAMING_SNAKE_CASE. Paste your text and get a clean result in real time.
No sign-up. No installation. Works on any device, completely free. Perfect for developers working with config keys, environment variables, and constant values in code.
Input Text
Output
The Constant Case Converter formats your text into CONSTANT_CASE the moment you paste or type it. Every letter goes uppercase. Every space becomes an underscore.
For example: max user count becomes MAX_USER_COUNT
It runs directly in your browser. No software to install, no account needed. Just open the page and start converting.
This tool is built for developers who need to name constants, config keys, or environment variables quickly and consistently. Inconsistent naming across a codebase causes confusion during code reviews and can lead to hard-to-catch bugs. This tool keeps your formatting clean every time.
Looking for a fast constant case converter online? You found it.
What Is Constant Case?
Constant case is a naming format where every letter is uppercase and words are separated by underscores. There are no spaces. No lowercase letters.
Examples: USER_ID, API_KEY, DEFAULT_TIMEOUT
It is also called SCREAMING_SNAKE_CASE or MACRO_CASE. All three terms refer to the same format.
Developers use constant case to name values that do not change, such as fixed settings, environment variables, and configuration keys. When you see a name written in constant case, you know right away it holds a fixed value. That is the point. The format acts as a visual signal inside your code.
Most major programming style guides require this format for constants. Python’s PEP 8 guide says constants should be written in all uppercase with underscores separating words. The Google Java Style Guide follows the same rule. JavaScript developers using tools like ESLint often enforce constant case for values declared with const at the module level.
Many programming languages and frameworks also expect this format for specific settings. Environment variable names in .env files, for example, are almost always written in constant case: DATABASE_URL, PORT, NODE_ENV.
What Does the Constant Case Converter Do?
The Constant Case Converter takes any text you paste or type and converts it into CONSTANT_CASE format. It capitalizes every letter and replaces spaces with underscores.
Here are a few quick examples:
Input | Output |
user id | USER_ID |
api key | API_KEY |
max retry limit | MAX_RETRY_LIMIT |
database connection url | DATABASE_CONNECTION_URL |
The conversion happens in real time. You do not need to click a button or wait for the page to reload. As soon as you type or paste your text, the output is ready.
The tool also handles common formatting problems automatically. It strips extra spaces, detects camelCase and PascalCase words, and splits them correctly before converting. So if you paste getUserName, the tool outputs GET_USER_NAME without any manual cleanup from you.
This makes it useful beyond basic text. You can paste variable names from existing code, column headers from a spreadsheet, or raw phrases from a doc, and the tool will output clean CONSTANT_CASE every time.
How To Use the Constant Case Converter
Converting text takes less than 10 seconds. Here is exactly how it works.
Step 1 — Paste or Type Your Text
Click the input box on the left and type your text directly, or paste it in. You can enter a single word, a short phrase, or multiple lines at once.
Step 2 — Get Your Result Instantly
The output appears in the right box as you type. No button to click. No page reload. Your text is converted to CONSTANT_CASE in real time.
For example: user login count becomes USER_LOGIN_COUNT the moment you type it.
Step 3 — Copy or Download the Output
Three icons sit next to the output box:
- Clipboard icon — copies the converted text to your clipboard
- Download icon — saves the output as a text file
- Word icon — copies the result in .docx format
Step 4 — Use the Settings to Clean Up Your Input
At the bottom of the tool you will find three checkboxes. These give you more control over how your input is handled:
- Strip whitespace from both sides — removes leading and trailing spaces before converting
- Use each line as a separate value — converts each line on its own, useful when pasting a list of variable names
- Detect camelCase and PascalCase words — splits compound words automatically before converting. So getUserEmail becomes GET_USER_EMAIL without any manual editing
These settings are especially useful when you are pasting text copied from existing code or spreadsheets where formatting is inconsistent.
What Makes This Constant Case Converter Better?
There are plenty of case conversion tools online. Most are cluttered, slow, or built as an afterthought inside a larger text utility. This tool is built specifically for developers who need clean, fast constant case output without distractions.
Here is what sets it apart:
No Button to Click
Most online converters ask you to paste your text and then hit a “Convert” button. This tool converts in real time as you type or paste. The output is ready before you finish reading it.
Handles camelCase and PascalCase Input
If you paste variable names from existing code, the tool recognizes camelCase and PascalCase patterns and splits them correctly. getUserEmail becomes GET_USER_EMAIL. maxRetryLimit becomes MAX_RETRY_LIMIT. You do not need to reformat your input manually before converting.
Multiple Output Options
Once your text is converted, you can copy it to your clipboard, download it as a text file, or export it in .docx format. That covers most workflows without needing to open another tool.
Works on Any Device
The tool runs in your browser. There is nothing to install. It works on desktop, tablet, and mobile. Whether you are at your desk or reviewing code on your phone, the converter is ready.
Free With No Sign-Up Required
No account. No trial period. No paywall. Open the page and start converting right away.
FAQs
What is constant case?
Constant case is a naming format where every letter is uppercase and words are separated by underscores. There are no spaces. Example: API_KEY, MAX_RETRY_LIMIT, DATABASE_URL. It is also called SCREAMING_SNAKE_CASE or MACRO_CASE. Developers use it to name values that do not change, such as fixed settings and environment variables.
What is the difference between constant case and snake_case?
Both formats use underscores between words. The difference is capitalization. Snake case uses all lowercase letters: user_id. Constant case uses all uppercase letters: USER_ID. Snake case is common for variable and function names. Constant case is reserved for values that never change.
Is SCREAMING_SNAKE_CASE the same as constant case?
Yes. SCREAMING_SNAKE_CASE and constant case refer to the same format. MACRO_CASE is another name for it. All three mean the same thing: uppercase letters with underscores between words.
Who should use this tool?
This tool is built for developers, coders, and technical writers who need to format constants, config keys, environment variables, or variable names quickly. It is also useful for anyone working with .env files, database column names, or Redux action types.
Is the Constant Case Converter free?
Yes. It is 100% free to use. No sign-up, no account, and no payment required.
Do I need to install anything?
No. The tool runs directly in your browser. Just open the page and start converting.
Does it work on mobile?
Yes. It works on all modern browsers including mobile. The layout adjusts to fit your screen size.
Can I use it for large blocks of text?
Yes. You can paste short phrases or large blocks of text. The tool converts everything instantly. Use the “treat each line as a separate value” setting if you are pasting a list of items and want each one converted on its own.