Free Case Converter
Two audiences, one tool: writers and programmers
People reach for a case converter for two quite different reasons. Writers want to fix text typed with the wrong capitalisation: a paragraph in all capitals, a heading in lowercase, a list that needs a consistent style. Programmers want to turn plain words into the naming style their language expects. The twelve formats here cover both, and they all run in your browser, so nothing you type is sent anywhere.
For writers
- UPPER CASE is for short labels and emphasis. Long stretches of capitals are hard to read, so use it sparingly.
- lower case rescues text typed with Caps Lock on, and is useful for tags and email addresses.
- Sentence case capitalises the first letter of each sentence and is the natural style for body text and many headings.
- Capitalize Each Word capitalises every word, suited to names and some display headings.
- Title Case follows common headline rules and leaves small words in lowercase. For a particular style guide, the title case converter offers AP, APA and Chicago options.
For programmers: which case where
| Format | Example | Common home |
|---|---|---|
| camelCase | userFirstName | JavaScript and Java variables and functions |
| PascalCase | UserFirstName | Class and component names in many languages |
| snake_case | user_first_name | Python variables, database columns |
| kebab-case | user-first-name | URLs, CSS classes, file names |
| CONSTANT_CASE | USER_FIRST_NAME | Constants and environment variables |
Conventions vary between teams and frameworks, so follow the one your project already uses.
The fun ones
aLtErNaTiNg and iNVERSE are mostly for jokes and memes, though inverse has a practical use for fixing text typed with Caps Lock accidentally on while Shift was held. Use them for fun, and know they are not suited to anything serious.
Where converters trip up
- Names and the pronoun I. Sentence case will lowercase a name in the middle of a sentence, and a word like iPhone or McDonald may need fixing by hand.
- Acronyms in code names. A phrase such as HTTP server can become httpServer or hTTPServer depending on the rules, so check the result against your project’s style.
- Numbers and symbols. They stay where they are, which sometimes produces names like user_2_name that you will want to tidy.
- Languages without capitals. Bengali, Hindi, Arabic and many others have no upper and lower case, so these formats leave their letters alone.
A handy workflow for renaming variables
- Write the name as plain words: shipping address line two.
- Paste it in and click the format your language uses.
- Copy the result,
shippingAddressLineTwoorshipping_address_line_two. - Use the result as input to produce the other formats, which is handy when a field has a different name in the front end, the back end and the database.
A walk-through: from heading to code names
Start with the phrase monthly sales report. As Title Case it is Monthly Sales Report, good for a document heading. As camelCase it is monthlySalesReport, good for a JavaScript variable. As PascalCase it is MonthlySalesReport, good for a class or component. As snake_case it is monthly_sales_report, good for a Python function or a database column. As kebab-case it is monthly-sales-report, good for a page address or CSS class. As CONSTANT_CASE it is MONTHLY_SALES_REPORT, good for a setting. One phrase, six homes, in a few seconds of clicking.
Cleaning pasted text
Text copied from PDFs and old systems often has a stray mix of capital letters. Convert it to lowercase first, then to sentence case, and you have a clean base to edit. Use Use result as input to chain conversions without copying and pasting between steps.
Naming consistency across a project
Pick one convention per layer, such as camelCase in the front end and snake_case in the database, and write it in your project notes. The converter makes moving between them painless, and consistent names make code far easier to search and review.
Capitals and accessibility
Whole sentences in capital letters are harder to read for many people, because the shapes of words become uniform. They can also feel like shouting. If you want emphasis, bold type or a short capitalised word usually works better than capitalising a whole line. For headings that must look capitalised, many designers apply uppercase through the page styling, so the underlying text stays in normal case.
FAQ
Paste the text and click lower case, or Sentence case to keep capitals at the start of sentences.
camelCase starts with a lowercase letter, such as myValue. PascalCase starts with a capital, such as MyValue.
Words in lowercase joined by underscores, such as user_id. It is common in Python and databases.
Yes. Letters with accents and other alphabets that have upper and lower case are converted correctly.
No. Conversion happens in your browser.
Yes. Paste as many lines as you like. Each line is converted according to the format you choose, and line breaks are kept for the plain case styles.