Best Open Source Alternatives to LangSmith

Compare the best free and open-source alternatives to LangSmith — self-hosted and desktop replacements you fully control, ranked by GitHub stars, license and platform support.

Curated by open-source.store · Updated August 2026 · 3 alternatives

LangSmith

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LangSmith alternatives compared

Open-source alternatives to LangSmith, compared by stars, license and platform
Tool		License	Platforms	Self-hosted
Langfuse	32,279	MIT	LinuxDockerWeb	Yes	Aug 2026	Visit
Promptflow	11,209	MIT	LinuxmacOSWindows	No	Jul 2026	Visit
Phoenix	10,852	Apache-2.0	LinuxmacOSWindows	No	Aug 2026	Visit