Open Source Alternatives
Open Source Observability Alternatives to LangSmith
LangChain's hosted platform for tracing, evaluating, and monitoring LLM applications and AI agents in production.
LangSmith is a trademark of its respective owner.
Updated Jun 2026
What you gain
- ✓Trace and eval data stays on your own infrastructure, not LangChain's cloud
- ✓No per-seat fee as your team grows past the free tier
- ✓Works with any framework, not just LangChain and LangGraph
- ✓Full control over data retention and PII handling
What you give up
- △No managed Prompt Hub or hosted annotation queues out of the box
- △Lose LangSmith's one-click LangChain and LangGraph trace instrumentation
- △You run and scale the trace storage yourself
- △No vendor SLA or dedicated support engineer
Switching Cost
Switching off LangSmith means swapping the LangSmith SDK for another tracing client and re-pointing your instrumentation, then standing up a self-hosted backend like Langfuse or Phoenix. A solo dev on one app can move in a day or two; a small team with several agents in production should budget a week to re-instrument and validate parity. The hidden cost is your historical trace and evaluation datasets: they don't come with you, so you either export what you can or accept starting your observability history fresh.
| Langfuse | phoenix | latitude-llm | |
|---|---|---|---|
| Overlap | 70% | 65% | 60% |
| Migration | moderate | moderate | moderate |
| License | MIT License | Other | LGPL-3.0 |
| Best for | Small teams | Small teams | Small teams |
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Drop-in Replacements
Ranked by feature coverage
Langfuse
8170% coverageOpen source LLM engineering platform
Langfuse is the observability platform for LLM applications: traces every call, measures latency and cost, tracks quality over time. It traces every LLM call, shows you the prompts, completions, latency, costs, and lets you evaluate output quality over time.
phoenix
6965% coverageAI Observability & Evaluation
Phoenix is open source observability for AI apps. When an LLM feature misbehaves in production, this is how you see why.
latitude-llm
6160% coverageLatitude is the open-source ai monitoring platform.
Latitude watches your AI agents the way Datadog watches your servers. When you ship an app built on LLMs, you lose visibility the moment a prompt leaves your code, you can't see why an agent went off the rails or which step failed.