newlines

A newline, or line break, is a character or sequence that marks the end of one line of text and the start of another. It allows plain text to be displayed across multiple lines.

Historically, different systems used different newline conventions. Unix and modern Unix-like systems use a line feed character (LF). Classic Macintosh systems used a carriage return (CR). Windows typically uses a carriage return followed by a line feed (CRLF).

In ASCII and Unicode, the characters are code points U+000A for LF and U+000D for CR. In UTF-8 these occupy single bytes. Some files use CRLF to represent a single newline, others use LF only; some old Mac files use CR only.

Programming languages often provide escape sequences for newlines, such as \n or \r\n, and many languages support universal newline mode that accepts any common end-of-line convention when reading text. Tools that process text, including compilers, version control systems, and editors, may normalize or convert line endings to a standard form.

In text rendering and the web, newline handling can differ. In HTML, actual newlines in source are typically collapsed unless inside preformatted blocks or styled with whitespace preservation. Protocols such as HTTP require CRLF as the line terminator. Consistent handling of line endings aids cross-platform collaboration.