In July 2023, Meta open-sourced its large language model (LLM), Llama 2, contrasting OpenAI’s proprietary GPT-4 model. While Llama 2 is smaller and potentially faster, GPT-4 boasts superior performance in task complexity, coding, math reasoning, and multilingual capacity. Access to Llama 2’s source code introduces transparency, but GPT-4’s closed-source nature offers a competitive advantage. Both models present unique cost structures and considerations around data privacy and security. The choice between the two models hinges on project requirements, complexity, and specific use cases.