Overview
Capitalisation is a dress code, and every community enforces its own. Publishers want title case on headings and sentence case on body copy; programmers mark word boundaries with camelCase humps or snake_case underscores because code cannot contain spaces; data teams standardise column names before a single query runs. Get the convention wrong and the error is small but oddly loud — and retyping to fix it invites fresh typos.
This converter treats case as a mechanical transform. It first recovers the underlying words — splitting camelCase humps, mixed separators and stray punctuation — then rebuilds them under the rules of whichever of the thirteen styles you choose. Original and result live in separate boxes, so experimenting never destroys the source.
Why do thirteen case styles exist?
Because different readers need different signals. Publishing tradition gave us sentence case and title case to mark what kind of text we are looking at. Programming gave us camelCase and PascalCase for variables and classes, snake_case for functions and files, kebab-case for URLs and CSS, and CONSTANT_CASE as a visual promise that a value must never change. Each is the same operation — split into words, rejoin with new rules — wearing different clothes.
The clever part is the splitting. A naive converter lowercases everything and calls it done, which mangles userFirstName into userfirstname. True word detection reads the capital-letter boundaries first, so conversions work in every direction: user_first-name becomes userFirstName and back again, losslessly.
Features
- Thirteen styles — upper, lower, sentence, title, camel, Pascal, snake, kebab, constant, alternating, inverse and more.
- True word detection that splits camelCase humps and mixed separators before rebuilding.
- Non-destructive: input and output boxes are separate, so the original is never lost.
- Chainable — feed the result back in and apply a second style with one click.
- Cleanup transforms for stray whitespace and broken line breaks from pasted text.
- Live counts on both boxes showing characters and words before and after.
- Copy or download the result as clipboard text or a .txt file.
Benefits
- No retyping, no new typos. Conversion cannot introduce the errors typing always risks.
- One convention everywhere. Normalise mixed naming styles across a whole file in seconds.
- Draft first, style later. Write naturally, then format headings and variables at the end.
- Rescue messy pastes. PDF and spreadsheet debris cleans up before styling.
Who can use it
Developers renaming variables and database columns, writers styling headings and titles, students formatting references, marketers preparing CMS copy, and office workers untangling text copied from PDFs. Anyone who has ever held shift and retyped a heading by hand will feel the saving immediately.
How to use
- Paste or type your text into the input box.
- Click the style you want — the result appears in the output box.
- Compare styles freely; the original never changes.
- Copy the result, or download it as a text file.
- Chain another conversion by feeding the result back as input.
Frequently asked questions
Will converting destroy my original text?
Never — that is the core design guarantee. Every conversion writes only to the output box while the input box keeps exactly what you typed. Run all thirteen styles against the same original, compare them side by side, chain one into another: the source text remains untouchable through all of it.
How does it convert text that is already camelCase?
It splits on capital-letter boundaries first, recovering the underlying words, then rebuilds them under the target style's rules. That structural reading — words rather than characters — is what makes every-direction conversion possible, so userFirstName becomes user_first_name and back again without loss. Mixed inputs like user_first-name are handled the same way, since separators are just another kind of word boundary to the splitter.
Title case or sentence case for my heading?
Follow your style guide, because the two conventions signal different things. Most publishers put headings in title case — significant words capitalised, short connectors small — and references in sentence case. This tool's title case follows that mainstream rule, so its output matches what editors expect to see.
What is CONSTANT_CASE actually for?
A programming convention that shouts “this value is fixed.” Configuration keys, environment variables and enum members are written in shouting capitals with underscores as a visual contract: do not reassign this. The style exists so that a reader spots immutability before reading a single line of documentation.
Can it clean up text pasted from a PDF?
The cleanup transforms handle the usual damage from hostile sources: collapsed whitespace, stray tabs and line breaks stranded mid-sentence. Run cleanup first to repair the structure, then apply your case style to the mended text — the two steps together rescue most pasted messes. Heavily damaged text may still need a human eye afterwards, but the common cases — the ones that eat an afternoon — disappear in two clicks.
Does my text leave my browser?
No. Every transform is plain JavaScript running in your tab. There is no upload step, no processing queue and no trace left behind — close the tab and the text is gone as if it was never there. That is true for every tool on this site, not just this one: the architecture has no place for your text to go.
Conclusion
Case is structure wearing typography's clothes — and structure should be applied by rule, not retyped by hand. Pick a style, click once, and let the words underneath rearrange themselves.