RightLeft

Right-to-left, abbreviated RTL, is a writing and layout direction in which text flows from the right side of a page to the left. It is used for scripts in which the majority of letters are ordered from right to left, and it also governs the alignment of user interfaces and documents in those languages. RTL is often contrasted with left-to-right (LTR).

Several scripts are primarily right-to-left, including Arabic, Hebrew, Persian (Farsi), Urdu, and Kurdish. Other languages use RTL scripts but also include left-to-right segments, requiring bidirectional text handling. Some languages historically used RTL scripts but now use mixed directions in modern technology.

In computing, bidirectional text is managed by the Unicode Bidirectional Algorithm, which determines how characters with different directional properties mix in a single line. In web development, the base direction can be set with dir="rtl" on a document or element, or via CSS direction: rtl. Unicode provides control characters such as Right-to-Left Mark (U+200F) to influence direction, and Left-to-Right Mark (U+200E). Embedding and override characters (RLE, RLO, etc.) allow finer control.

Typography and punctuation pose challenges: parentheses and quotation marks may appear on the opposite side, and punctuation may attach to the preceding word. Numerals can be displayed in the local numeric system while the surrounding text remains RTL. Layout considerations include mirroring of icons, alignment of text, and text justification.

Understanding RTL is essential for multilingual publishing, user interfaces, and software internationalization.