In Cebuano-speaking communities in the Central Visayas and Mindanao regions of the Philippines, speakers exhibit differences in the frequency of code-switching on Twitter. Geographic and historic factors drive cultural and linguistic diversification on Mindanao, which Twitter data shows to have drifted farthest from Cebu in terms of code-switching frequency. An isolating geography, a conflict-filled history between the islands, and cultural, ethnic and linguistic diversity on Mindanao provide the basis for the claim that the divergence in code-switching practices may truly reflect an underlying divergence in cultural identity in Cebuano speaking communities in these areas.