Arabic Letter Forms: 28 Letters and Joining Rules

The 28-letter shape table

The contextual cells deliberately show Unicode compatibility glyphs for visual identification against the chart. Do not copy those cells into application text; the Copy table button copies only the base letters, code points and joining column. A dash means no distinct initial or medial joining form exists; glyph appearance still depends on the available font.

Six letters break onward joining

Alef, dal, thal, reh, zain and waw can join a preceding letter on their right, but do not join the following letter on their left. Reading order and screen direction are different concepts: “onward” here means the next letter in the logical text sequence.

The table covers the conventional 28 basic letters, not every letter in the Arabic block. Hamza variants, teh marbuta, alef maksura and letters used in other Arabic-script languages require additional cases. Do not infer a complete shaping algorithm from this teaching table.

Store letters, let the renderer shape them

In application strings, use ordinary base letters in logical order. A shaping engine chooses contextual glyphs using the font. Unicode discourages encoding the contextual shapes as characters for general interchange; that would couple stored text to a visual form.

const word = "\u0643\u062A\u0628"; // base letters, logical order
// HTML example: <span lang="ar" dir="rtl">...</span>
// Never replace each letter with a FE** presentation-form character.

Debug joining without rewriting content

Guidance: check the original code points, font coverage, direction markup and unexpected format controls before changing text. Keep a representative set of words with initial, medial and final joins in visual regression checks. Use the range reference to distinguish encoded letters from compatibility forms.