Overview
RTF, or Rich Text Format, is a document file format created by Microsoft that stores formatted text along with basic structural elements like tables, images, and font specifications using plain-text control codes. Unlike binary formats such as the old .doc, an RTF file can be opened in any text editor and read — albeit with difficulty — because its content is encoded as ASCII characters interspersed with backslash-prefixed control words like \b for bold and \par for paragraph breaks.
RTF was designed as an interchange format, enabling documents to move between different word processors while preserving basic formatting. It supports character-level formatting (fonts, sizes, colors, bold, italic, underline), paragraph-level formatting (alignment, indentation, line spacing), tables, embedded images (as hex-encoded data), and headers and footers. However, it lacks many features found in modern formats like DOCX, such as tracked changes, advanced layout controls, and embedded multimedia.
Despite its age, RTF remains useful in specific niches. It is commonly generated by clipboard operations on Windows, used as a safe format for email composition in some clients, and employed in legal and medical software where simple formatted text exchange is needed without the complexity of XML-based formats.
History
Microsoft introduced RTF in 1987 with the release of Word 3.0 for Macintosh, positioning it as a cross-platform document interchange format. The original specification (RTF 1.0) supported basic character and paragraph formatting. Over the following two decades, Microsoft released updated specifications culminating in RTF 1.9.1 in 2008, which added support for new Word features like mathematical equations and themes.
RTF achieved widespread adoption in the 1990s as the primary interchange format between Word, WordPerfect, and other word processors. However, with the rise of DOCX and ODF in the late 2000s, RTF usage declined significantly. Microsoft officially stopped updating the RTF specification after version 1.9.1 and recommends DOCX or PDF for document interchange. Nevertheless, many legacy systems and specialized applications continue to rely on RTF.
Technical Details
An RTF file is a plain-text stream composed of groups delimited by curly braces, control words prefixed with backslashes, and literal text. The file begins with {\rtf1 followed by character set and font table declarations. A typical control word like \fs24 sets the font size to 12 points (RTF measures font size in half-points). Groups nest to create scoped formatting: {\b bold text} applies boldface only within the braces.
Images are embedded as hexadecimal-encoded data within \pict groups, specifying the image type (e.g., \pngblip for PNG, \jpegblip for JPEG), dimensions, and the raw hex bytes. Tables are defined using \trowd (table row default), \cellx (cell boundary positions in twips — 1/1440 of an inch), and \cell delimiters. Because all data is encoded as printable ASCII, RTF files are significantly larger than equivalent binary or compressed XML formats, but they are resilient to partial corruption and trivial to generate programmatically.
Pros & Cons
Pros
- Human-readable plain-text encoding that any text editor can open
- Extremely broad compatibility across word processors and operating systems
- Simple programmatic generation without needing XML or ZIP libraries
- Resilient to partial corruption since content is plain ASCII
- Safe from macro-based malware unlike .doc and .docm formats
Cons
- No support for tracked changes, comments, or modern collaboration features
- Hex-encoded images inflate file sizes dramatically compared to compressed formats
- Limited layout control — no master pages, columns, or advanced typography
- Specification has not been updated since 2008 and is effectively deprecated
- Rendering inconsistencies between applications for complex formatting
Common Use Cases
- Exchanging formatted text between disparate word processors and legacy systems
- Generating simple formatted documents programmatically from code without complex libraries
- Clipboard interchange on Windows where rich formatting must survive copy-paste
- Legal document assembly systems that need a lightweight formatted-text format
- Email composition in clients that use RTF as their internal editor format