Text Case Converter

Sentence case needs one extra click, and here is why

The most important thing on this page, because Sentence case is the conversion people most often want and it has a real flaw.

It only works properly on text that is already lowercase. Give it text that is shouting and it fixes the first letter of each sentence but leaves the rest capitalised — and worse, it lowercases the second letter of each sentence, so ALL CAPS input comes back looking mangled rather than merely unchanged.

The fix is two extra clicks, using a feature that is already here:

Click lowercase first. Click Swap, which moves the result back into the input box. Now click Sentence case. You get exactly what you wanted.

That sequence is worth remembering, because pasting a block of shouty text — an email in caps, a form export, a spreadsheet column — and wanting readable sentences is the single commonest reason anyone opens a case converter.

The Swap button is useful well beyond this. Any conversion can feed the next one: strip the special characters, swap, then convert to snake_case. Remove the line breaks, swap, then fix the capitalisation. Each conversion reads whatever is in the input box, so nothing is destroyed and you can try all seventeen against the same text without repasting.

Title Case here is not really title case

Being honest about the second limitation, because it will bite anyone formatting a headline.

Title Case capitalises every word, including the small ones. So "the lord of the rings" becomes "The Lord Of The Rings" — where every style guide in existence wants "The Lord of the Rings", with the articles and short prepositions left lowercase.

For a heading of three or four words you will not notice. For a long title, a book chapter or anything going through an editor, you will have to lowercase the small words by hand: a, an, the, and, but, or, for, nor, at, by, in, of, on, to, up, as, if — while still capitalising the first and last word whatever they are.

Most online converters share this exact flaw, so this is not unusually bad. It is just worth knowing rather than discovering in print.

The seven programmer cases, and which to use where

This is the part most case converters skip, and the reason to bookmark this one.

camelCase — first word lowercase, each following word capitalised, no separators. JavaScript and Java variables and functions.

PascalCase — every word capitalised, no separators. Class and type names in most languages, and React component names.

snake_case — all lowercase, underscores between words. Python variables and functions, Ruby, and database column names.

kebab-case — all lowercase, hyphens between words. URL slugs, CSS class names, HTML attributes and file names on the web. This is the one to use for a page address, because search engines read hyphens as word breaks and underscores as part of the word.

SCREAMING_SNAKE — uppercase with underscores. Constants and environment variables in nearly every language.

dot.case — lowercase joined by full stops. Configuration keys, translation keys and package namespaces.

path/case — lowercase joined by slashes. Route definitions and file paths.

The practical use is bulk renaming: paste a list of names in one convention, convert the lot, and paste them back. Converting a column of database fields to camelCase for an API response, or a set of labels to kebab-case for URLs, is a few seconds instead of a manual pass.

One real limitation: all seven keep only unaccented letters and digits. Accented characters and non-Latin scripts — Arabic, Urdu, Chinese, Cyrillic, Greek — are dropped entirely rather than converted, so "café menu" loses its accented letter and a heading in Arabic comes back empty. That is fine for code, since identifiers are ASCII anyway, but do not run non-English prose through these seven.

The four cleanup operations

Useful and easy to overlook, sitting at the end of the row.

Remove Extra Spaces collapses runs of spaces and tabs to one and trims the ends — the fix for text copied out of a PDF or a badly formatted document.

Remove Line Breaks joins the lines into one paragraph, and importantly it puts a space where the break was, so words do not run together. That is the behaviour you want when un-wrapping a paste from a PDF, and it is worth knowing this version does it correctly.

Remove Numbers strips every digit, and Remove Special Chars keeps only letters, digits and spaces. Both are blunt by design. Run Remove Special Chars before a programmer-case conversion and the result is noticeably cleaner, because the punctuation is gone before the separators are chosen.

The other two prose conversions are novelties with occasional uses: Toggle Case inverts every letter, which fixes text typed with Caps Lock on in one click. aLtErNaTiNg exists for the internet.

How it behaves

Two boxes side by side, with a running count of characters and words under each — handy on its own for checking a text against a length limit.

The output box is read-only, so to edit a result you Swap it into the input first. Copy Result gives you no confirmation that it worked, so glance at the output box rather than assuming, particularly if your browser has ever asked you about clipboard permission. There is no download — this is a copy-and-paste tool, which is what a case converter should be.

Nothing is transmitted. The conversions run entirely in your browser, which matters more than it sounds for this tool: the text people paste into a case converter is routinely client names, email lists, internal field names and unreleased copy.

Related tools

Word Counter gives you a full breakdown — sentences, paragraphs, reading time — when the counts here are not enough. Line Break Remover handles line breaks on their own with more control than the single operation here. Duplicate Line Remover strips repeated lines out of a list, which pairs well with a case conversion when you are tidying data.