How to use the Case Converter
Online text case converter for writing and code
A case converter changes letter capitalization without requiring you to retype the text manually. This page works as an uppercase converter, lowercase converter, title case converter, sentence case converter, capitalization tool, toggle case converter and developer naming converter in one browser-based workspace. It is useful when text arrives in ALL CAPS, when a heading needs consistent title capitalization, or when a phrase must become a programming-style identifier such as camelCase or snake_case.
The source and converted result are shown separately. That means you can compare the transformation before replacing the original text. If the result should become the next source, use Use Result as Input and apply another transformation.
Supported case formats
| Case style | Example | Typical use |
|---|---|---|
| UPPERCASE | HELLO WORLD | Headings, labels, emphasis and fixing mixed capitalization. |
| lowercase | hello world | Removing accidental Caps Lock and normalizing text. |
| Title Case | A Guide to Better Writing | Headlines, titles and subject lines using configurable small-word rules. |
| Sentence case | Hello world. This is text. | Normal prose after text has been entered in inconsistent capitalization. |
| Capitalized Case | Hello World From Here | Capitalizing the first cased letter of every detected word. |
| Alternating case | hElLo WoRlD | Stylized, playful or meme-like text. |
| Inverse / toggle case | hELLO wORLD | Flipping existing uppercase letters to lowercase and vice versa. |
| camelCase | helloWorld | JavaScript variables, object properties and general identifiers. |
| PascalCase | HelloWorld | Class names, components, types and exported identifiers. |
| snake_case | hello_world | Python-style names, database fields and configuration keys. |
| kebab-case | hello-world | CSS classes, URL-like labels and readable identifiers. |
| CONSTANT_CASE | HELLO_WORLD | Constants and environment-style variable names. |
| dot.case | hello.world | Namespaced keys, settings and dot-separated identifiers. |
Uppercase to lowercase and lowercase to uppercase
For the simplest capitalization fixes, choose UPPERCASE to capitalize every caseable letter or lowercase to convert it to small letters. This is useful for accidental Caps Lock text, email subjects, copied headings, spreadsheet labels, social captions and text extracted from documents. The transformation preserves punctuation, numbers, spaces and line breaks.
Title Case vs Sentence case
Title Case is intended for headings and titles. With Smart English small-word rules enabled, short function words such as “a”, “an”, “the”, “and”, “or”, “of”, “in”, “on” and “to” remain lowercase in the middle of a title while the first and last detected words stay capitalized. Sentence case lowercases normal words and capitalizes the first cased letter of each detected sentence. These are different editorial conventions, so the tool keeps them as separate modes.
camelCase, PascalCase, snake_case and kebab-case converter
Developer case conversion first identifies word boundaries, including common transitions in existing identifiers such as myVariableName or XMLHttpRequest. It can then rebuild those words as camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE or dot.case. These formats are useful when moving names between JavaScript, TypeScript, Python, databases, CSS, configuration files and APIs.
Unicode and language-aware capitalization
The converter uses modern browser internationalization features where available instead of assuming that every language is English or that every word is separated by an ASCII space. Locale-aware upper/lowercase mappings can matter for languages such as Turkish and Azerbaijani. The locale selector lets you request a specific mapping when needed, while Auto uses the browser's normal locale behavior.
Word, sentence and visible-character statistics use Intl.Segmenter when the browser supports it. This improves segmentation for scripts and languages where simple split(" ") logic is inaccurate. Older browsers fall back to Unicode-aware regular-expression logic.
Useful reasons to change text case
Privacy, performance and browser compatibility
The text case conversion logic runs in this page inside your browser. The tool does not need an external conversion library or a server request to change the capitalization of the text you enter. It also does not add its own analytics system, rating database or public usage counter. Very large text can take longer to transform depending on the device, but the page does not impose an arbitrary text-length limit.
Modern versions of Chrome, Edge, Firefox and Safari provide the strongest Unicode segmentation behavior. If Intl.Segmenter is unavailable, the converter falls back to Unicode-aware text handling for the core transformations and counts.
Troubleshooting case conversion
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Frequently Asked Questions
What is a case converter?
A case converter changes the capitalization pattern of text. It can turn text into uppercase, lowercase, Title Case, Sentence case, Capitalized Case, alternating case or developer naming formats without manually retyping each letter.
Can I convert uppercase to lowercase?
Yes. Paste the all-caps text into Original text and choose lowercase. Punctuation, digits, spaces and line breaks remain in place while caseable letters are converted.
Can I convert lowercase to uppercase?
Yes. Choose UPPERCASE to convert supported lowercase letters into uppercase using the selected locale's casing behavior where available.
What is the difference between Title Case and Capitalized Case?
Title Case can keep common short English words lowercase in the middle of a title. Capitalized Case capitalizes the first cased letter of every detected word without applying the English small-word list.
Does Sentence case work with multiple sentences?
Yes. Modern browsers use locale-sensitive sentence segmentation through Intl.Segmenter. A Unicode-aware fallback is used when that API is unavailable.
What are camelCase, PascalCase, snake_case and kebab-case?
They are common identifier naming conventions. camelCase starts with a lowercase word, PascalCase capitalizes each word, snake_case joins lowercase words with underscores, and kebab-case joins lowercase words with hyphens.
Does the converter support Unicode and non-English text?
Uppercase and lowercase use JavaScript's locale-aware case mapping. Word and sentence segmentation uses Intl.Segmenter when supported, which improves behavior for many scripts and languages compared with splitting only on spaces.
Why does Title Case sometimes differ from AP, APA, Chicago or MLA?
Different style guides use different capitalization rules. The built-in smart Title Case provides practical English small-word handling, but publication-specific rules may require a final editorial adjustment.
Can I download converted text?
Yes. After choosing a case style, use Download TXT. The UTF-8 filename begins with correctioncopy.com_ as part of the site's download naming convention.
Is there a text length limit?
The page does not impose an arbitrary character limit. Practical capacity depends on browser memory and device speed, so extremely large text may take longer to segment or transform.
Is my text uploaded for case conversion?
No server-side conversion is required. The capitalization logic runs in the browser. The page also does not add a separate Firebase counter or rating database.
Can I edit the converted result before copying it?
Yes. The Converted text box remains editable. You can make a final manual adjustment, then copy or download that edited result.