Case Converter

How to use it

1. Paste or type your text in the first box.
2. Click the case you want, UPPERCASE, lowercase, Title Case, Sentence case, capitalized or alternating.
3. Copy the converted result with the Copy result button.

What is letter case conversion?

Letter case conversion changes which letters are capital and which are small, without touching the words themselves. The two jobs people need most are turning lowercase into uppercase, usually called all caps or capital letters, and turning capitals back into lowercase. Both are a straight swap applied to every letter, so the result is exact.

UPPERCASE   every letter becomes a capital    hello -> HELLO
lowercase   every letter becomes small         HELLO -> hello
Title Case  capitalize major words, keep short joining words small

Title Case and Sentence case follow rules instead of a simple swap. Title Case capitalizes each major word but leaves words like a, of and the lowercase unless they come first, last or after a colon. Sentence case capitalizes only the first word of each sentence. Every mode uses Unicode rules, so accented and Cyrillic letters convert the same way plain letters do.

Worked example

The same sentence in every mode

Title case rules by style guide

AP and APA capitalize prepositions of four or more letters; Chicago lowercases prepositions no matter how long. Every guide capitalizes the first and last word of a title, and verbs are always capitalized, however short.

Uppercase, lowercase and the other cases

Most case changes are one of two jobs. Converting lowercase to uppercase, also called all caps or capital letters, makes a heading, a warning or a code constant stand out. Converting uppercase to lowercase fixes text that arrived in capitals, such as a spreadsheet export or a message typed with Caps Lock on. UPPERCASE is the default mode here, so pasted text is converted to capital letters straight away.

When all caps helps, and when it hurts

Capital letters work for short labels, acronyms, legal notices and single-line headings, where they signal importance. They work badly for anything longer. A paragraph in all caps is slower to read, because the words lose the shapes the eye relies on, and in email or chat it reads as shouting. For long passages, Sentence case is the better target.

Title Case capitalizes the first letter of each major word and is standard for headlines and the titles of books, films and articles. This case converter follows common headline style: short joining words such as a, an, the, of, to, in, for and via stay lowercase unless they begin or end the title or follow a colon or period. Sentence case capitalizes only the first word of each sentence, the way ordinary prose is written.

Capitalize Each Word uppercases the first letter of every word, small words included, which suits menu labels, product names and form fields. Apostrophes are respected, so don't becomes Don't and O'Brien stays O'Brien. aLtErNaTiNg case switches letter by letter for meme captions and has no serious use.

Shortcuts in other apps

Microsoft Word cycles selected text through lowercase, UPPERCASE and Capitalize Each Word when you press Shift+F3. Google Docs has the same options under Format, Text, Capitalization. In Excel and Google Sheets, =UPPER converts a cell to all caps, =LOWER to lowercase and =PROPER capitalizes each word. None of them offers headline-style Title Case that leaves of and the lowercase.

Every mode uses the browser's built-in Unicode rules, so accented, Greek and Cyrillic letters convert correctly. In UPPERCASE élan becomes ÉLAN, and in Title Case über becomes Über. Nothing you paste leaves your device.

Common uses

• Formatting headlines and titles correctly
• Fixing text that was typed with Caps Lock on
• Preparing names, labels and menu items
• Creating stylized aLtErNaTiNg text for social posts
• Cleaning up all-caps or all-lowercase pasted text
• Converting spreadsheet exports that arrived in capitals
• Standardizing product names and email subject lines

When to use it

• You need to convert lowercase to uppercase for a heading, a label or a code constant.
• Text arrived in all caps, like a spreadsheet export full of shouting product names, and you want it in lowercase.
• You typed a paragraph with Caps Lock on and would rather fix it than retype it.
• A headline needs proper title case and you cannot remember whether to capitalize a preposition like with.
• A list of customer names arrived in mixed case and every entry should read First Last, capitalized.

Related tools

Slug Generator goes further than lowercase: it also strips accents and symbols and joins words with hyphens for a clean URL.

Word Counter checks length and reading time once the capitalization is fixed, useful for headlines with a character budget.

Find and Replace Text handles changes a case mode cannot, such as swapping one recurring word or fixing a repeated typo.