Open-source alternatives guide · Updated 2026

Best open-source alternatives to Langsmith

Q: How should I evaluate Langsmith alternatives?

Map must-have Langsmith workflows, verify license and compliance fit, run a proof of concept with real data and integrations, then plan ownership for upgrades, backups, support, and an exit path.

Compare the best free and open-source alternatives to LangSmith — 7 verified projects with explicit catalog relationships. Inspect licenses, GitHub activity, self-hosting signals, and migration fit before you switch.

7verified alternatives
2self-hosted signals
1category

Only explicit alternative relationships are shown—never inferred competitor claims.

Overview

This guide compares 7 verified open-source alternatives to LangSmith, including Langfuse, Arize Phoenix, OpenLLMetry, and Helicone.

Projects appear mainly in AI & Machine Learning. 2 options include a self-hosting signal — see the self-hosted catalog. Ranking follows public GitHub stars and recorded momentum—not vendor marketing. Compare projects side by side, then confirm license fit, migration effort, and operational ownership before adopting any option.

Strongest repository-activity signal: Langfuse · Jump to ranking · 31.2K stars · self-hostable

About LangSmith

Proprietary product with documented open-source alternatives cataloged on OpenSourceChoice. Compare licenses, repository activity, and self-hosting options befo

Ranked open-source alternatives to LangSmith

Compare capabilities, licensing, and ownership model. Stars help with discovery; they are not a security or product-fit guarantee.

Langfuse

Open-source alternative to LangSmith

AI & Machine LearningLicense not declaredSelf-hostedAI-native

🪢 Open source AI engineering platform: LLM evals, observability, metrics, prompt management, playground, datasets. Integrates with OpenTelemetry, LangChain, OpenAI SDK, LiteLLM, and more. 🍊YC W23

🪢 Open source AI engineering platform: LLM evals, observability, metrics, prompt management, playground, datasets. Integrates with OpenTelemetry, LangChain, OpenAI SDK, LiteLLM, a

Best for: AI product teams
Deployment: Self-hostable
License: License not declared
Activity: Updated 26 hours ago

Key capabilities

self-hosted

open-source

llm

analytics

Arize Phoenix

Open-source alternative to LangSmith

AI & Machine LearningLicense not declaredAI-native

AI Observability & Evaluation

AI Observability & Evaluation Review the official repository, license, release activity, and deployment documentation before production adoption.

Best for: AI product teams
Deployment: Inspectable source
License: License not declared
Activity: Updated 26 hours ago

Key capabilities

openai agents

anthropic

langchain

OpenLLMetry

Open-source alternative to LangSmith

AI & Machine LearningApache-2.0AI-native

Open-source observability for your GenAI or LLM application, based on OpenTelemetry

Open-source observability for your GenAI or LLM application, based on OpenTelemetry Review the official repository, license, release activity, and deployment documentation before p

Best for: AI product teams
Deployment: Inspectable source
License: Apache-2.0
Activity: Updated 3 days ago

Key capabilities

open-source

python

llm

monitoring

Helicone

Open-source alternative to LangSmith

AI & Machine LearningApache-2.0AI-native

🧊 Open source LLM observability platform. One line of code to monitor, evaluate, and experiment. YC W23 🍓

🧊 Open source LLM observability platform. One line of code to monitor, evaluate, and experiment. YC W23 🍓 Review the official repository, license, release activity, and deploymen

Best for: AI product teams
Deployment: Inspectable source
License: Apache-2.0
Activity: Updated 12 days ago

Key capabilities

open-source

llm

analytics

openai

Latitude

Open-source alternative to LangSmith

AI & Machine LearningMITSelf-hostedAI-native

Latitude is the open-source ai monitoring platform.

Latitude is the open-source ai monitoring platform. Review the official repository, license, release activity, and deployment documentation before production adoption.

Best for: AI product teams
Deployment: Self-hostable
License: MIT
Activity: Updated 27 hours ago

Key capabilities

Agenta

Open-source alternative to LangSmith

AI & Machine LearningLicense not declaredAI-native

The open-source LLMOps platform: prompt playground, prompt management, LLM evaluation, and LLM observability all in one place.

The open-source LLMOps platform: prompt playground, prompt management, LLM evaluation, and LLM observability all in one place. Review the official repository, license, release acti

Best for: AI product teams
Deployment: Inspectable source
License: License not declared
Activity: Updated 28 hours ago

Key capabilities

agents

observability llmops llm-observability

OpenLIT

Open-source alternative to LangSmith

AI & Machine LearningApache-2.0AI-native

Open source platform for AI Engineering: OpenTelemetry-native LLM Observability, GPU Monitoring, Guardrails, Evaluations, Prompt Management, Vault, Playground. 🚀💻 Integrates with 50+ LLM Providers, VectorDBs, Agent Fra

Open source platform for AI Engineering: OpenTelemetry-native LLM Observability, GPU Monitoring, Guardrails, Evaluations, Prompt Management, Vault, Playground. 🚀💻 Integrates with

Best for: AI product teams
Deployment: Inspectable source
License: Apache-2.0
Activity: Updated 27 hours ago

Key capabilities

How to choose a LangSmith alternative

Map must-have capabilitiesList the workflows in LangSmith you cannot drop during migration.

Verify the licenseConfirm it fits your use, distribution, and compliance model. Browse license briefs.

Run a proof of conceptTest real data, integrations, clients, and failure modes. Use Compare for side-by-side checks.

Plan ownershipAssess upgrades, backups, support, and an exit path. Read when self-hosting is worth it.

Frequently asked questions about LangSmith alternatives

What are the best open-source alternatives to LangSmith?

OpenSourceChoice currently lists 7 projects with an explicit alternative relationship to LangSmith. Catalog highlights include Langfuse, Arize Phoenix, and OpenLLMetry. Rankings follow public GitHub stars and recorded momentum—not paid placement. Match capabilities and license fit to your workflow before adopting any option.

Are open-source alternatives to LangSmith free?

Most catalogued alternatives publish source under OSI or source-available licenses and are free to inspect. Hosting, commercial support, or cloud model APIs may still cost money. Always read the project license for your use case.

Can I self-host an alternative to LangSmith?

2 options in this list carry a self-hosting signal. Confirm the official install guide, backups, upgrades, and hardening steps before production.

How should I evaluate LangSmith alternatives?

Map must-have LangSmith workflows, verify license and compliance fit, run a proof of concept with real data and integrations, then plan ownership for upgrades, backups, support, and an exit path.