PhoGPT

PhoGPT is an open-source generative model series for Vietnamese from VinAI Research (Vingroup), unveiled at AI Day 2023. It comes in two sizes: PhoGPT-7B5, a 7.5B-parameter monolingual model with an instruction-tuned variant, and PhoGPT-4B, a 3.7B-parameter model pre-trained from scratch on 102 billion Vietnamese tokens with an 8192-token context length and a Vietnamese-specific byte-level BPE tokenizer of 20,480 types. The chat variants were fine-tuned on tens of thousands of instructional prompts plus hundreds of thousands of conversations. VinAI reported human evaluations placing PhoGPT-7B5-Instruct just below closed-source GPT-3.5-turbo, and the models are released for wide-ranging use including commercial purposes.\n\nThe honest picture: PhoGPT is a narrow specialist — excellent for Vietnamese text generation but not a multilingual generalist, and its architecture (2023-era decoder with Flash Attention and AliBi) predates modern reasoning advances. Still, it remains one of the few genuinely monolingual open models for Vietnamese and is free for commercial use.