> ## Documentation Index > Fetch the complete documentation index at: https://docs.trusys.ai/llms.txt > Use this file to discover all available pages before exploring further. # Functional Evaluation TRU EVAL enables structured, scalable evaluation of AI models across custom or standardized metrics. Descriptive alt text ### Key Capabilities * Run prompt-based evaluations against custom datasets or shared benchmarks * Compare multiple models (e.g., GPT-4, Claude, custom LLMs) * Supports both **reference-based** and **referenceless evaluation** (also known as “LLM-as-a-judge”) * Visualize performance across key capabilities such as factuality, reasoning, helpfulness * Track regression or improvement in model behavior over time ### Use Cases * Score open-source vs proprietary models * Tailor evaluation templates to organizational needs * Measure model alignment to domain-specific requirements