Respan
Nested traces for every LLM call, tool run, and agent turn
The top alternatives to Arize AI in the Observability, Prompts & Evals space, compared on features, pricing, and what they're best at.
Updated March 9, 2026
Arize AI is a unified LLM observability and agent evaluation platform designed for AI application development and production management. The platform enables teams to build, observe, and improve AI systems through integrated development and production capabilities. Built on OpenTelemetry standards and open-source principles, Arize features 'adb,' a proprietary datastore optimized for generative AI workloads with real-time ingestion and sub-second query capabilities. The platform includes an agent framework for building and debugging AI agents, comprehensive tracing for full visibility into LLM application flows, automated evaluators with custom evaluation models, and Alyx, an AI engineering agent that assists with debugging and development. Arize offers experiment testing and optimization capabilities, production monitoring and alerting, a prompt playground for optimization, and data annotation tools. With impressive scale processing 1 trillion spans, 50 million evaluations per month, and 5 million monthly downloads of Phoenix OSS, Arize serves notable clients including DoorDash, Instacart, Reddit, Roblox, Uber, and Booking.com.
Respan
Nested traces for every LLM call, tool run, and agent turn
LangSmith
Native tracing for LangChain and LangGraph
Weights & Biases
ML experiment tracking
MLflow
OpenTelemetry-based tracing for LLMs and agents
Langfuse
Tracing for LLM calls, tool runs, and agent steps
Traceloop
OpenTelemetry
Datadog LLM
LLM monitoring within Datadog platform
Helicone
HoneyHive
Prompt management
Braintrust
Experiments comparing prompts and models
Phoenix
OpenTelemetry-based LLM and agent tracing
Patronus AI
Automated LLM evaluation platform
Promptfoo
Portkey
Humanloop
Ragas
RAG-specific evaluation framework
Sentry
DeepEval
LangWatch
Multi-turn agent simulation testing
Galileo AI
LLM output quality evaluation
PromptLayer
Confident AI
DeepEval open-source evaluation framework
Maxim AI
Distributed tracing for LLM and agent apps
Opik
Agenta
Future AGI
Multimodal evaluation (text, image, audio, video)
Lunary
Parea AI
Ashr
Multi-modal synthetic testing
Sentrial
Agent failure root cause analysis
Chamber
ML infrastructure automation
Moda
Hallucination detection
Athina AI
Laminar
Agent tracing with a readable transcript view
OpenObserve
Logs, metrics, traces, RUM, and session replay
AgentOps
Session replay with time-travel debugging
Fiddler AI
Agentic observability across multi-step agent workflows
One platform for routing, observability, tracing, and evals across every LLM provider.
Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.
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