0x000D

0x000D is the hexadecimal code point for the Carriage Return (CR) control character. In ASCII, it has the decimal value 13, and in Unicode it is represented as U+000D. It is a non-printing control character that moves the cursor to the beginning of the current line without advancing to the next line.

Historically, CR is central to newline conventions. Windows text files typically use a CR followed by a Line Feed (CRLF) as a line terminator. Classic Mac OS used CR on its own in some contexts, while Unix and Unix-like systems standardize on Line Feed (LF, 0x0A) as the newline character. The presence of CR in data is often tied to these historical and platform-specific line-ending formats.

In programming and data formats, CR is commonly represented in strings by the escape sequence \r in many languages. It appears in network protocols and data formats that require CRLF line endings, such as HTTP, SMTP, and various email-related standards. In Unicode, CR is categorized as a C0 control code and does not have a visible glyph or character shape.

Related control characters include LF (0x0A) and the CRLF sequence (0x0D 0x0A). The legacy and cross-platform use of CR means software often must handle mixed or optional line endings to avoid parsing or security issues, such as improper handling of line terminators in text processing or input validation.