The Arabic chat alphabet, Arabizi, Franco-Arabic (franco-arabe), refer to the Romanized alphabets for informal Arabic dialects in which Arabic script is transcribed or encoded into a combination of Latin script and Arabic numerals. These informal chat alphabets were originally used primarily by youth in the Arab world in very informal settings—especially for communicating over the Internet or for sending messages via cellular phones—though use is not necessarily restricted by age anymore and these chat alphabets have been used in other media such as advertising.

These chat alphabets differ from more formal and academic Arabic transliteration systems, in that they use numerals and multigraphs instead of diacritics for letters such as qāf (ق) or ḍād (ض) that do not exist in the basic Latin script (ASCII), and in that what is being transcribed is an informal dialect and not Standard Arabic. These Arabic chat alphabets also differ from each other, as each is influenced by the particular phonology of the Arabic dialect being transcribed and the orthography of the dominant European language in the area—typically the language of the former colonists, and typically either French or English.

Because of their widespread use, including in public advertisements by large multinational companies, large players in the online industry like Google and Microsoft have introduced tools that convert text written in Arabish to Arabic (Google Translate and Microsoft Translator). Add-ons for Mozilla Firefox and Chrome also exist (Panlatin and ARABEASY Keyboard ). The Arabic chat alphabet is never used in formal settings and is rarely, if ever, used for long communications.