# Alternatives to LangSmith 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. 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. Source: https://altcatalog.com/alternatives/langsmith/ Category: AI evaluation platforms ## Overview - **Who it's for**: 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. - **What you get**: 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). - **How it works**: 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. ## Profile - **License**: Proprietary (platform); MIT (client SDK) (verified 2026-07-17) - **Pricing model**: Freemium (verified 2026-07-17) - **Starts at**: $39/seat/mo (verified 2026-07-17) - **Platforms**: Web - **Status**: active (verified 2026-07-17) ## Ranked alternatives | # | App | Alt Score | Licence | Platforms | |---|-----|-----------|---------|-----------| | 1 | [Comet Opik](https://altcatalog.com/alternatives/comet-opik.md) | 100 | Apache-2.0 | Web | | 2 | [Langfuse](https://altcatalog.com/alternatives/langfuse.md) | 100 | MIT | Web | | 3 | [Arize Phoenix](https://altcatalog.com/alternatives/arize-phoenix.md) | 96 | Elastic License 2.0 (ELv2) | Web | | 4 | [Braintrust](https://altcatalog.com/alternatives/braintrust.md) | 96 | Proprietary (platform); MIT (autoevals library) | Web | | 5 | [HoneyHive](https://altcatalog.com/alternatives/honeyhive.md) | 93 | Proprietary | Web | | 6 | [W&B Weave](https://altcatalog.com/alternatives/wandb-weave.md) | 93 | Apache-2.0 | Web | | 7 | [Helicone](https://altcatalog.com/alternatives/helicone.md) | 76 | Apache License 2.0 | Web | Alt Score = Verified coverage (90%) + Visibility (10%). See https://altcatalog.com/how-alt-score-works/ ## Feature comparison Legend: Yes / No / Partial / ? (not verified). | AI evaluation platforms checklist | LangSmith | Comet Opik | Langfuse | Arize Phoenix | Braintrust | HoneyHive | |---|---|---|---|---|---|---| | Pricing model | Freemium | OSS + paid hosting | OSS + paid hosting | Free | Freemium | Freemium | | Starts at | $39/seat/mo | $19/month (USD) | $29/month (USD) | Free | $249/month | Free | | License | Proprietary (platform); MIT (client SDK) | Apache-2.0 | MIT | Elastic License 2.0 (ELv2) | Proprietary (platform); MIT (autoevals library) | Proprietary | | Platforms | Web | Web | Web | Web | Web | Web | | Open source | No | Yes | Yes | Partial | Partial | No | | Self-hostable | Yes | Yes | Yes | Yes | Yes | Yes | | Tracing / observability | Yes | Yes | Yes | Yes | Yes | Yes | | Prompt playground & versioning | Yes | Yes | Yes | Yes | Yes | Yes | | Dataset management | Yes | Yes | Yes | Yes | Yes | Yes | | LLM-as-judge evals | Yes | Yes | Yes | Yes | Yes | Yes | | Human annotation / review | Yes | Yes | Yes | Yes | Yes | Yes | | Online (production) monitoring | Yes | Yes | Yes | Yes | Yes | Yes | | A/B experiments | Yes | Yes | Yes | Yes | Yes | Yes | | CI / regression testing | Yes | Yes | Yes | Yes | Yes | Yes | | Cost & token tracking | Yes | Yes | Yes | Yes | Yes | Yes | | Framework-agnostic SDK | Yes | Yes | Yes | Yes | Yes | Yes | | Free tier | Yes | Yes | Yes | Yes | Yes | Yes | ## Sources Sources for LangSmith. Each alternative is sourced on its own page. - **Pricing model**: Freemium — (verified 2026-07-17) - Quote: “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” - **Starts at**: $39/seat/mo — (verified 2026-07-17) - Quote: “Plus For teams building and deploying agents. $39 / seat per month then pay as you go” - **Status**: active — (verified 2026-07-17) - Note: 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 - Quote: “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).” - **Platforms**: Web — (verified 2026-07-17) - Note: 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. - Quote: “In the LangSmith UI, go to Tracing and select your default project.” - **License**: Proprietary (platform); MIT (client SDK) — (verified 2026-07-17) - Note: 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 - Quote: “MIT License Copyright (c) 2023 LangChain” - **Open source**: No — (verified 2026-07-17) - Note: The LangSmith platform requires a commercial license key even for self-hosting; only the client SDK (langsmith-sdk) is MIT-licensed open source. - Quote: “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” - **Self-hostable**: Yes — (verified 2026-07-17) - Quote: “Host an instance of LangSmith in your own infrastructure for observability, evaluation, and prompt engineering.” - **Tracing / observability**: Yes — (verified 2026-07-17) - Quote: “LangSmith Observability provides full visibility into your LLM application: from individual traces to production-wide performance metrics.” - **Prompt playground & versioning**: Yes — (verified 2026-07-17) - Quote: “Open the Playground ... Test and experiment with prompts using custom endpoints and model configurations.” - **Dataset management**: Yes — (verified 2026-07-17) - Quote: “LangSmith provides tools for managing and working with your datasets. This page describes dataset operations including: Versioning datasets to track changes over time.” - **LLM-as-judge evals**: Yes — (verified 2026-07-17) - Quote: “This guide shows you how to define an LLM-as-a-judge evaluator for offline evaluation using the LangSmith UI.” - **Human annotation / review**: Yes — (verified 2026-07-17) - Quote: “Annotation queues give human reviewers a focused workflow for attaching feedback to specific runs.” - **Online (production) monitoring**: Yes — (verified 2026-07-17) - Quote: “Online Evaluation: Monitor in production. Evaluate real user interactions in real-time to detect issues and measure quality on live traffic.” - **A/B experiments**: Yes — (verified 2026-07-17) - Quote: “LangSmith supports a comparison view that lets you identify key differences, regressions, and improvements between different experiments.” - **CI / regression testing**: Yes — (verified 2026-07-17) - Quote: “Track assertions in LangSmith and raise assertion errors locally (e.g. in CI pipelines).” - **Cost & token tracking**: Yes — (verified 2026-07-17) - Quote: “LangSmith automatically records LLM token usage and costs for major providers, and also allows you to submit custom cost data for any additional components.” - **Framework-agnostic SDK**: Yes — (verified 2026-07-17) - Quote: “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” - **Free tier**: Yes — (verified 2026-07-17) - Quote: “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” --- Ranked by verified data, never by who paid. https://altcatalog.com/trust/