Case Converter

Convert text between upper case, lower case, capitalized case, sentence case, and normalize with space. Type or paste your text in the box below, then click the desired transformation button. The character and word counters update in real time.

Character count: 0 Word count: 0 Current case:

About Each Case Format

Upper Case (ABC)

Converts every letter to its capital form; all non-letter characters (digits, punctuation, spaces) are left unchanged. Commonly used for acronyms (NASA, HTML, SQL), brand logotypes (IBM, IKEA), legal headings, and safety warnings.

Lower Case (abc)

Converts every letter to its small form; all non-letter characters remain unchanged. The default convention for body text, URL paths, file names on Unix/Linux, CSS class names, and variable names in most programming languages.

Capitalized Case (Abc)

Capitalizes the first letter of every word, leaving all other characters unchanged. Used for book and film titles, product names, navigation menu items, and column headers where each word carries equal typographic weight.

Sentence Case (Ab.)

Capitalizes only the first character of the text and the first character after any ". " (period followed by a space). The standard style for body text and the recommended convention in modern design systems (Material Design, Fluent UI, GitHub) for UI labels and button text.

Normalize with Space (a. b)

Applies two corrections: inserts a space after any period(.) or comma(,) not already followed by one, and collapses multiple consecutive spaces into a single space. Useful for cleaning text extracted from PDFs or pasted from spreadsheets - apply to plain prose only, not to URLs or code.

Quick Examples

Upper Case: "hello world. this is a test." → "HELLO WORLD. THIS IS A TEST."
Lower Case: "HELLO WORLD. THIS IS A TEST." → "hello world. this is a test."
Capitalized Case: "hello world. this is a test." → "Hello World. This Is A Test."
Sentence Case: "hello world. this is a test." → "Hello world. This is a test."
Normalize with Space: "hello world,this is a test." → "hello world, this is a test."