Case converter

1. Type or paste text in the source box.

2. Choose a case mode in Converter settings; the result updates instantly.

3. Copy the converted result and paste it where you need it.

A case converter changes ordinary letter case and common identifier styles. It keeps your text local to your browser and does not create fancy Unicode text or small caps.

Uppercase and lowercase use the en-US locale on letters. Digits, emoji, and punctuation stay as typed. Title Case capitalizes the first letter after whitespace and lowercases the rest of that word; it is not AP headline style and will happily capitalize “of” and “the”. Sentence Case capitalizes the first letter of the whole string and lowercases other letters, so a second sentence after a period is not detected. Alternating case flips letter by letter for a joke, not for a cipher. camelCase and snake_case tokenize on Latin letters and digits; other scripts and emoji act as separators or are dropped from identifier tokens.

Input is limited to 500 graphemes. Longer paste is truncated, which is visible in the count. Conversion runs in your browser. This case converter will not map A to Mathematical Bold A, will not produce true small caps, and will not title-case a citation list to Chicago rules. Those jobs need a style guide or a font. If you need Unicode fashion letters, use fancy text. If you need a programming identifier from a sentence, camel and snake modes are a start, not a full inflector: they do not singularize words or expand abbreviations.

Programmers use camelCase and snake_case when renaming a label. The tokenizer here is Latin-centric on purpose. A Japanese sentence will not become useful camelCase. Accents on Latin letters may remain if the locale keeps them; they are still letters. Punctuation between words becomes a boundary. Leading digits can produce identifiers that some languages reject; the converter will still emit them. Read the result before you paste it into source control.

Writers use title and sentence modes to fix a shouty paragraph or a lowercased chat log. Title Case on a whole essay looks like a hostage note; use it on headings. Sentence Case on a heading that should stay title case will flatten later words. There is no “smart” exception list. Alternating case is for memes. None of the modes translate language. A Spanish title will follow the same whitespace rule as English, which is not always how Spanish headings are written.

Related writing tools reverse text or decorate it with combining marks. Run those after you pick a case, or you will reverse mixed case into a new puzzle. Copy is plain text. Destinations that force their own case (some URL slugs, some usernames) will ignore your paste. Games that allow mixed case in a display name usually accept the result. Password fields should not be case-converted unless you meant to change the password.

Accessibility: screaming caps can be harder to read and can be announced poorly. Prefer sentence case for long text. Screen readers will still read camelCase as a single word unless they split on caps; that is a reader setting, not something this page injects. Do not use alternating case for warnings that must be understood quickly.

When a form asks for “title case,” confirm whether they mean this simple rule or a house style. When a linter asks for snake_case, this mode is close enough for Latin tokens. When a designer asks for small caps, this is the wrong tool. The live mode tabs are the contract: seven explicit transforms, one source, one result, local.

Try a short sample in the destination. Excel, Docs, and IDEs each have their own case commands that stay editable as formatting or as a formula. Those are better when the text never leaves that file. Use this case converter when you need the changed letters themselves in a chat, a CMS field, or a config file. If the result looks truncated, you hit the grapheme limit; shorten the source rather than assuming a bug in title case.

Batch cleanup is the other common job: a chat export in all caps, a heading typed in lowercase, a list of labels that must become snake_case for a config file. Run one mode, copy, paste, then read. Title Case will not leave “iPhone” alone. Sentence Case will flatten acronyms. camelCase will drop punctuation that you might have wanted as part of a token. Those surprises are cheaper to catch on a ten-word sample than on a whole document. Nothing here is undo except your editor’s undo after paste, so keep the original buffer.

Use Uppercase for all caps and Lowercase to normalize text.

Title Case capitalizes each whitespace-separated word. Sentence Case capitalizes only the first letter of the whole string and lowercases the rest.

Identifier modes use Latin letters and digits, so punctuation, emoji, and other scripts act as separators.