Alternatives to LangSmith
LLM observability, evaluation, and prompt engineering from the LangChain team.
LangSmith ranks #6 of 8 in AI evaluation platforms, with an Alt Score of 93. It is licensed under Proprietary (platform); MIT (client SDK), freemium from $39/seat/mo and available on the web. 13 of 13 checklist rows are verified against a public source.
LangSmith is a platform for debugging, testing, evaluating, and monitoring LLM applications, with tracing, datasets, and LLM-as-judge evaluations. Built by LangChain and framework-agnostic.
Development teams building LLM-powered applications and agents — from solo developers prototyping with the free Developer plan to enterprise teams needing SSO, RBAC, and self-hosted or hybrid deployment. It integrates natively with LangChain and LangGraph but is designed to trace, evaluate, and monitor any LLM application, including ones built with OpenAI, Anthropic, CrewAI, Vercel AI SDK, and other frameworks.
A unified platform for LLM application observability (tracing and dashboards), offline and online evaluation (datasets, LLM-as-judge and code evaluators, pairwise and single-run annotation queues), prompt engineering (a Playground with prompt versioning and a public prompt hub), and cost/token tracking, plus optional agent deployment tooling (Agent Server, Studio).
Developers instrument their application with the LangSmith SDK (Python or JS/TS, MIT-licensed client) or framework integrations to send traces to LangSmith; teams then build evaluation datasets, attach automated or human-reviewed evaluators to score runs offline (regression testing, CI via a pytest plugin) or online against live production traffic, and monitor results through dashboards and alerts. The platform is offered as a fully managed cloud SaaS (smith.langchain.com), a hybrid deployment, or a self-hosted Enterprise add-on requiring a license key from LangChain.
Why people leave LangSmith
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Ranked alternatives
Ordered by Alt Score. Click any score to see the breakdown.
Opik is an open-source LLM evaluation platform from Comet for tracing, evaluating, and monitoring LLM applications, with datasets, LLM-as-judge metrics, and a prompt playground.
Langfuse is an open-source LLM engineering platform providing tracing, prompt management, evaluations, datasets, and analytics for LLM applications; self-hostable or cloud.
Phoenix is an open-source observability and evaluation library from Arize AI for tracing, evaluating, and troubleshooting LLM applications, built on OpenTelemetry.
Braintrust is an evaluation and observability platform for AI products, with datasets, LLM-as-judge scorers, prompt playground, and production logging.
HoneyHive is an AI evaluation and observability platform for testing, tracing, and monitoring LLM applications, with datasets, LLM-as-judge evaluators, and human review.
Weave is the Weights & Biases toolkit for tracking, evaluating, and monitoring LLM applications, with tracing, scorers, and experiment comparison.
Feature comparison
Rows come from the AI evaluation platforms checklist (17 rows). Human-verified cells only. ? means the value has not been verified.
| AI evaluation platforms checklist | LangSmith | Comet Opik | Langfuse | Arize Phoenix | Braintrust | HoneyHive |
|---|---|---|---|---|---|---|
| Pricing model | ||||||
| Starts at | ||||||
| License | ||||||
| Platforms | ||||||
| Open source | ||||||
| Self-hostable | ||||||
| Tracing / observability | ||||||
| Prompt playground & versioning | ||||||
| Dataset management | ||||||
| LLM-as-judge evals | ||||||
| Human annotation / review | ||||||
| Online (production) monitoring | ||||||
| A/B experiments | ||||||
| CI / regression testing | ||||||
| Cost & token tracking | ||||||
| Framework-agnostic SDK | ||||||
| Free tier |
Every fact and feature listed for LangSmith is verified against its own pages. Each alternative is sourced on its own page.
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Pricing model Freemium verified 2026-07-17
Developer For solo users getting started. $0 / seat per month then pay as you go Start for free Up to 5k base traces / mo, then pay-as-you-go
https://www.langchain.com/pricing-langsmith -
Starts at $39/seat/mo verified 2026-07-17
Plus For teams building and deploying agents. $39 / seat per month then pay as you go
https://www.langchain.com/pricing-langsmith -
Status active verified 2026-07-17
Docs page shows new regional infrastructure shipped in the months immediately preceding this research (current date July 2026), indicating ongoing active development rather than an explicit 'actively
As of April 2026, LangSmith SaaS is available on AWS in us-east-2 (Ohio). ... As of May 2026, LangSmith SaaS is available in APAC on GCP in australia-southeast1 (Sydney).
https://docs.langchain.com/langsmith/cloud.md -
Platforms Web verified 2026-07-17
LangSmith is a hosted web application (smith.langchain.com) plus client SDKs (Python, JS/TS, Java); SDKs are not part of the allowed platforms enum so only Web is recorded.
In the LangSmith UI, go to Tracing and select your default project.
https://docs.langchain.com/langsmith/observability-quickstart -
License Proprietary (platform); MIT (client SDK) verified 2026-07-17
The langsmith-sdk client library is MIT licensed, but the LangSmith platform itself is closed-source/proprietary — self-hosting requires a license key from LangChain's sales team, not a public source
MIT License Copyright (c) 2023 LangChain
https://raw.githubusercontent.com/langchain-ai/langsmith-sdk/main/LICENSE -
Open source No verified 2026-07-17
The LangSmith platform requires a commercial license key even for self-hosting; only the client SDK (langsmith-sdk) is MIT-licensed open source.
Self-hosted LangSmith is an add-on to the Enterprise plan designed for our largest, most security-conscious customers. For more details, refer to Pricing. Contact our sales team if you want to get a l
https://docs.langchain.com/langsmith/self-hosted.md -
Self-hostable Yes verified 2026-07-17
Host an instance of LangSmith in your own infrastructure for observability, evaluation, and prompt engineering.
https://docs.langchain.com/langsmith/self-hosted.md -
Tracing / observability Yes verified 2026-07-17
LangSmith Observability provides full visibility into your LLM application: from individual traces to production-wide performance metrics.
https://docs.langchain.com/langsmith/observability.md -
Prompt playground & versioning Yes verified 2026-07-17
Open the Playground ... Test and experiment with prompts using custom endpoints and model configurations.
https://docs.langchain.com/langsmith/prompt-engineering.md -
Dataset management Yes verified 2026-07-17
LangSmith provides tools for managing and working with your datasets. This page describes dataset operations including: Versioning datasets to track changes over time.
https://docs.langchain.com/langsmith/manage-datasets.md -
LLM-as-judge evals Yes verified 2026-07-17
This guide shows you how to define an LLM-as-a-judge evaluator for offline evaluation using the LangSmith UI.
https://docs.langchain.com/langsmith/llm-as-judge.md -
Human annotation / review Yes verified 2026-07-17
Annotation queues give human reviewers a focused workflow for attaching feedback to specific runs.
https://docs.langchain.com/langsmith/annotation-queues.md -
Online (production) monitoring Yes verified 2026-07-17
Online Evaluation: Monitor in production. Evaluate real user interactions in real-time to detect issues and measure quality on live traffic.
https://docs.langchain.com/langsmith/evaluation.md -
A/B experiments Yes verified 2026-07-17
LangSmith supports a comparison view that lets you identify key differences, regressions, and improvements between different experiments.
https://docs.langchain.com/langsmith/compare-experiment-results.md -
CI / regression testing Yes verified 2026-07-17
Track assertions in LangSmith and raise assertion errors locally (e.g. in CI pipelines).
https://docs.langchain.com/langsmith/pytest.md -
Cost & token tracking Yes verified 2026-07-17
LangSmith automatically records LLM token usage and costs for major providers, and also allows you to submit custom cost data for any additional components.
https://docs.langchain.com/langsmith/cost-tracking.md -
Framework-agnostic SDK Yes verified 2026-07-17
LangSmith helps your team debug, evaluate, and monitor your language models and intelligent agents. It works with any LLM Application, including a native integration with the LangChain Python and Lang
https://raw.githubusercontent.com/langchain-ai/langsmith-sdk/main/README.md -
Free tier Yes verified 2026-07-17
Developer For solo users getting started. $0 / seat per month then pay as you go Start for free Up to 5k base traces / mo, then pay-as-you-go
https://www.langchain.com/pricing-langsmith
FAQ
Yes. Arize Phoenix, Braintrust and HoneyHive have a free tier or are fully free. Free-tier limits in the comparison table are verified and dated.
Comet Opik, Langfuse and Arize Phoenix — every license claim links its source.