37 Best PromptLayer Alternatives & Competitors (2026)

Respan

Nested traces for every LLM call, tool run, and agent turn

LangSmith

Native tracing for LangChain and LangGraph

MLflow

OpenTelemetry-based tracing for LLMs and agents

Weights & Biases

ML experiment tracking

Langfuse

Tracing for LLM calls, tool runs, and agent steps

Arize AI

ML observability with LLM support

Datadog LLM

LLM monitoring within Datadog platform

Helicone

Traceloop

OpenTelemetry

HoneyHive

Prompt management

Braintrust

Experiments comparing prompts and models

Promptfoo

Patronus AI

Automated LLM evaluation platform

Phoenix

OpenTelemetry-based LLM and agent tracing

Humanloop

Portkey

Ragas

RAG-specific evaluation framework

Sentry

DeepEval

LangWatch

Multi-turn agent simulation testing

Galileo AI

LLM output quality evaluation

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

Athina AI

Moda

Hallucination detection

Ashr

Multi-modal synthetic testing

Sentrial

Agent failure root cause analysis

Chamber

ML infrastructure automation

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