Fine-Tuning means training an existing AI model on your own data to customize its behavior. Takes a base model (GPT-4, Claude) and teaches it your specific patterns, style, or knowledge. More permanent than prompting—changes model weights. Requires 100-10,000 examples and costs money/time to train. Result: model that behaves consistently according to your needs. Use when prompting isn't good enough and you need permanent customization.
Fine-tune when: you need consistent behavior across thousands of calls, have 100+ high-quality training examples, few-shot prompting isn't accurate enough, or want to reduce prompt size (behavior baked into model). Don't fine-tune when: prompting works fine (cheaper, faster), you have <50 examples, or requirements change frequently. Fine-tuning is for production-scale, stable use cases.
Ai Vocabulary
Train AI on your specific data