Fiddler AI vs Weights & Biases

A side-by-side look at pricing, capabilities, pros, cons, and our editorial scores.

	Fiddler AI Evaluation	Weights & Biases Evaluation
Tagline	Enterprise AI observability and guardrails platform for monitoring agents, LLMs, and ML models in production.	The ML experiment tracker, now with LLM eval features.
Category	Evaluation	Evaluation
Pricing	Enterprise· Tiered plans; contact sales	Freemium· Free personal; team from $50/mo per seat
Model	Fiddler Centor (proprietary evaluators)	Platform (any LLM)
Editorial score	—	8.4 / 10
Use cases	llm-observabilityagent-monitoringai-guardrailsmodel-governancehallucination-detectioncompliance	ML experimentsLLM evalWeave
Pros	Purpose-built for regulated industries with deep governance and audit features Inline guardrails enforce policy in real time on request/response paths Proprietary Centor evaluator models reduce LLM-as-judge cost Covers agents, LLMs, and classical ML in one control plane	Industry-standard for ML tracking Weave adds LLM-native eval Mature, reliable Strong enterprise features
Cons	Enterprise sales motion; no transparent self-serve pricing Closed source with limited public technical detail Overkill for solo developers or small AI projects Setup and integration overhead vs. lightweight tracing tools	Heavier UX than LLM-native tools LLM features still catching up
Website	fiddler.ai	wandb.ai

Pick Fiddler AI if

✅ Purpose-built for regulated industries with deep governance and audit features
✅ Inline guardrails enforce policy in real time on request/response paths
✅ Proprietary Centor evaluator models reduce LLM-as-judge cost
✅ Covers agents, LLMs, and classical ML in one control plane

Pick Weights & Biases if