The 5 LLM Evaluation Metrics That Actually Matter in Production

We analyzed over 10,000 evaluation runs across 200+ production applications to find which metrics actually correlate with user satisfaction and business outcomes. The results may surprise you.

After extensive analysis, five metrics emerged as the strongest predictors of production success:

1. Faithfulness (correlation: 0.87) -- Does the response accurately reflect the source material?

2. Relevance (correlation: 0.82) -- Does the response actually answer the user's question?

3. Completeness (correlation: 0.79) -- Does the response cover all aspects of the query?

4. Latency P95 (correlation: -0.71) -- Users abandon after 3 seconds

5. Toxicity (correlation: -0.68) -- Even rare toxic outputs destroy trust

Notably absent: BLEU score, perplexity, and several other academic metrics that don't translate well to production settings.

All five metrics are available as built-in scorers in EvalGuard. Run them on every deployment to catch regressions before your users do.