{"id":17635,"date":"2025-10-29T22:20:54","date_gmt":"2025-10-29T22:20:54","guid":{"rendered":"https:\/\/www.comet.com\/site\/?page_id=17635"},"modified":"2026-08-10T17:18:27","modified_gmt":"2026-08-10T17:18:27","slug":"langsmith-vs-opik","status":"publish","type":"page","link":"https:\/\/www.comet.com\/site\/products\/opik\/compare\/langsmith-vs-opik\/","title":{"rendered":"LangSmith vs. Opik"},"content":{"rendered":"\n
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LangSmith vs. Opik: The Open-Source Alternative for AI Agent Observability and LLM Evaluation in 2026<\/strong><\/h1>\n\n\n\n

Last updated: 2026-07-30<\/em><\/p>\n\n\n\n

\"langsmith<\/figure>\n\n\n\n

Both tools trace, evaluate, and monitor LLM and agent applications. Opik is an open-source LLM and agent evaluation and observability platform built by Comet.<\/strong> LangSmith is the proprietary platform built by LangChain. The practical difference is where your data lives and what it costs to grow: Opik is Apache-2.0 with a free, full-feature self-host, while LangSmith reserves self-hosting for its Enterprise tier. If your stack is built on LangChain and LangGraph, LangSmith’s native path is genuinely the smoothest. If you want to own your traces or stay framework-neutral, Opik is built for that.<\/p>\n\n\n\n

The short answer<\/strong>: Choose Opik if you want to run evaluation and observability on your own infrastructure without an Enterprise contract, or if your agents are not all built on LangChain. Choose LangSmith if you are fully committed to the LangChain ecosystem and want the tightest native integration available.<\/p>\n<\/div>\n<\/div>\n\n\n\n

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What are the best alternatives to LangSmith in 2026?<\/h2>\n\n\n\n

The four platforms teams evaluate most often against LangSmith are Opik, Langfuse, Weights & Biases Weave, and Arize Phoenix. Listed with public GitHub footprint as of 2026-07-30, which is a reasonable proxy for how many teams can inspect and run the code themselves:<\/p>\n\n\n\n