This comparative study investigates how the distinct affordances of Instagram, Facebook, and TikTok differentially shape lexical and morpho-syntactic practices in Iraqi Arabic digital discourse among youth aged 18–29. Digital dialects are systematic, platform-mediated variations in online language shaped by technological affordances (Androutsopoulos, 2015). The study focused on educated male and female Iraqi youth from Baghdad and surrounding central regions, purposively selected based on Iraqi identity markers, public content visibility, and activity during January–April 2025. Analyzing a corpus of 900 textual units (300 per platform) through mixed-methods integrating Social Network Theory, Communities of Practice, and Arabic Diglossia, findings revealed platform-specific variation: TikTok exhibited the highest innovation density (12.4/100) with neologisms (35%) and fragmentation (38%); Instagram favored slang (37%) and politeness reduction (28%); and Facebook sustained elaborated foreign incorporations (42%) and verb conjugations (35%). Orthographic practices correlated strongly with constraint intensity—TikTok showed the strongest association between temporal pressure and Romanized Iraqi Arabic (ρ = 0.71, p < 0.001). Critically, 92% of lexical innovations and 88% of morpho-syntactic changes occurred exclusively in Colloquial Iraqi Arabic, with Modern Standard Arabic virtually absent (3–7%), signaling accelerated diglossic reconfiguration. The study concludes that platform architecture actively reshapes Iraqi Arabic's digital landscape, with implications for sociolinguistic theory, language education, and youth identity negotiation.
