The Fine-Tuning Index, recently announced, highlights the enhanced performance of fine-tuned open-source large language models (LLMs) in production settings, comparing them to leading commercial models like GPT-4 across 31 tasks. Based on over 700 experiments, the Index aids enterprise AI teams in selecting the best open-source models, revealing that fine-tuned models, such as Llama 3, Phi-3, and Zephyr, often outperform GPT-4, especially in specialized tasks like legal and medical applications. These models are not only more cost-effective and faster to train but also offer superior performance, with fine-tuning costing around $8 in compute resources per task. The Predibase research team's report, "LoRA Land: 310 Fine-tuned LLMs that Rival GPT-4, A Technical Report," delves into these findings, showcasing the potential of open-source LLMs and providing tools for organizations to leverage them effectively, thus democratizing access to advanced language models and facilitating the development of innovative AI products.