# 8 Best Open Source Alternatives for LangSmith Canonical: https://caniforkit.com/langsmith Last updated: 2026-11-07 Looking for the best open source alternative for LangSmith? Compare 8 verified free and open source alternatives to LangSmith (Langfuse, Arize Phoenix, OpenLLMetry) with license details, self-hosting requirements, and practical trade-offs. ## LangSmith Overview & Subscription Cost - **Product**: LangSmith - **Category**: [analytics](https://caniforkit.com/category/analytics) - **Paid Subscription Price**: $35/month per seat - **1-Seat Annualized Cost**: $420/year - **5-Person Team Annualized Cost**: $2,100/year - **10-Person Team Annualized Cost**: $4,200/year - **Can I Vibe-Code / Rebuild It Myself?**: NO (use a free alternative, save the tokens) - **Rebuild Verdict**: Instead of paying recurring SaaS fees for LangSmith or rebuilding it from scratch, deploy one of the 8 battle-tested open-source alternatives like Langfuse. ## Verified Free & Open Source Alternatives | Alternative | Type | License | Runs On | GitHub Stars | Head-to-Head | | --- | --- | --- | --- | --- | --- | | [Langfuse](https://caniforkit.com/fork/langfuse) | Open Source | Open Source | Self-host | ★ 37.1k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-langfuse) | | [Arize Phoenix](https://caniforkit.com/fork/arize-phoenix) | Open Source | Open Source | Self-host | ★ 12.2k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-arize-phoenix) | | [OpenLLMetry](https://caniforkit.com/fork/openllmetry) | Open Source | Open Source | Local | ★ 7.5k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-openllmetry) | | [Helicone](https://caniforkit.com/fork/helicone) | Open Source | Open Source | Local | ★ 6.3k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-helicone) | | [LangWatch](https://caniforkit.com/fork/langwatch) | Open Source | Open Source | Local | ★ 5k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-langwatch) | | [Latitude](https://caniforkit.com/fork/latitude) | Open Source | Open Source | Self-host | ★ 4.7k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-latitude) | | [OpenLIT](https://caniforkit.com/fork/openlit) | Open Source | Open Source | Self-host | ★ 3k | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-openlit) | | [Spanlens](https://caniforkit.com/fork/spanlens) | Open Source | Open Source | Self-host | ★ 13 | [Compare vs LangSmith](https://caniforkit.com/vs/langsmith-vs-spanlens) | ## In-Depth Alternative Profiles ### Langfuse - **Fork Page**: [Langfuse Profile](https://caniforkit.com/fork/langfuse) - **Head-to-Head Comparison**: [LangSmith vs Langfuse](https://caniforkit.com/vs/langsmith-vs-langfuse) - **Official Website**: https://langfuse.com/ - **Source Code Repository**: https://github.com/langfuse/langfuse - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 37.1k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Langfuse provides tracing, evaluations, prompt management, and analytics to debug and improve LLM applications. - **The Catch vs LangSmith**: Requires self-hosting setup, updates, and server maintenance compared to managed LangSmith. - **Installation**: Clone https://github.com/langfuse/langfuse or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### Arize Phoenix - **Fork Page**: [Arize Phoenix Profile](https://caniforkit.com/fork/arize-phoenix) - **Head-to-Head Comparison**: [LangSmith vs Arize Phoenix](https://caniforkit.com/vs/langsmith-vs-arize-phoenix) - **Official Website**: https://arize.com/phoenix/ - **Source Code Repository**: https://github.com/arize-ai/phoenix - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 12.2k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Open-source platform for LLM tracing, evaluation, and optimization. Features automatic instrumentation, prompt playground, and real-time AI application monitoring. - **The Catch vs LangSmith**: Requires self-hosting setup, updates, and server maintenance compared to managed LangSmith. - **Installation**: Clone https://github.com/arize-ai/phoenix or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### OpenLLMetry - **Fork Page**: [OpenLLMetry Profile](https://caniforkit.com/fork/openllmetry) - **Head-to-Head Comparison**: [LangSmith vs OpenLLMetry](https://caniforkit.com/vs/langsmith-vs-openllmetry) - **Official Website**: https://www.traceloop.com/openllmetry - **Source Code Repository**: https://github.com/traceloop/openllmetry - **License**: Open Source - **Runs On**: Local - **GitHub Stars**: 7.5k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: desktop, cross-platform, one-click install - **Summary**: Open-source observability platform for LLMs using OpenTelemetry. Monitor performance, track costs, and debug AI applications with just 2 lines of code. - **The Catch vs LangSmith**: Community-driven open source project without dedicated enterprise SLAs. - **Installation**: Clone https://github.com/traceloop/openllmetry or deploy with Docker Compose - **Setup**: Download the native package or installer for your operating system. - **Data Storage**: All application data lives locally on your own machine. ### Helicone - **Fork Page**: [Helicone Profile](https://caniforkit.com/fork/helicone) - **Head-to-Head Comparison**: [LangSmith vs Helicone](https://caniforkit.com/vs/langsmith-vs-helicone) - **Official Website**: https://helicone.ai - **Source Code Repository**: https://github.com/helicone/helicone - **License**: Open Source - **Runs On**: Local - **GitHub Stars**: 6.3k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: desktop, cross-platform, one-click install - **Summary**: Open-source platform for logging, monitoring, and debugging LLM applications. Route, debug, and analyze AI apps with comprehensive observability tools. - **The Catch vs LangSmith**: Community-driven open source project without dedicated enterprise SLAs. - **Installation**: Clone https://github.com/helicone/helicone or deploy with Docker Compose - **Setup**: Download the native package or installer for your operating system. - **Data Storage**: All application data lives locally on your own machine. ### LangWatch - **Fork Page**: [LangWatch Profile](https://caniforkit.com/fork/langwatch) - **Head-to-Head Comparison**: [LangSmith vs LangWatch](https://caniforkit.com/vs/langsmith-vs-langwatch) - **Official Website**: https://langwatch.ai/ - **Source Code Repository**: https://github.com/langwatch/langwatch - **License**: Open Source - **Runs On**: Local - **GitHub Stars**: 5k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: desktop, cross-platform, one-click install - **Summary**: Tests AI agents through multi-turn simulations, LLM-based scoring, and production tracing so teams can ship reliable agents with confidence. - **The Catch vs LangSmith**: Community-driven open source project without dedicated enterprise SLAs. - **Installation**: Clone https://github.com/langwatch/langwatch or deploy with Docker Compose - **Setup**: Download the native package or installer for your operating system. - **Data Storage**: All application data lives locally on your own machine. ### Latitude - **Fork Page**: [Latitude Profile](https://caniforkit.com/fork/latitude) - **Head-to-Head Comparison**: [LangSmith vs Latitude](https://caniforkit.com/vs/langsmith-vs-latitude) - **Official Website**: https://latitude.so/ - **Source Code Repository**: https://github.com/latitude-dev/latitude-llm - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 4.7k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Open-source platform for monitoring AI agents: captures traces, surfaces failure patterns, alerts on issues, and helps you verify fixes with automated evals. - **The Catch vs LangSmith**: Requires self-hosting setup, updates, and server maintenance compared to managed LangSmith. - **Installation**: Clone https://github.com/latitude-dev/latitude-llm or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### OpenLIT - **Fork Page**: [OpenLIT Profile](https://caniforkit.com/fork/openlit) - **Head-to-Head Comparison**: [LangSmith vs OpenLIT](https://caniforkit.com/vs/langsmith-vs-openlit) - **Official Website**: https://openlit.io/ - **Source Code Repository**: https://github.com/openlit/openlit - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 3k - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Open-source observability platform for GenAI and LLM applications. Real-time monitoring, distributed tracing, prompt management, and AI model evaluation built on OpenTelemetry. - **The Catch vs LangSmith**: Requires self-hosting setup, updates, and server maintenance compared to managed LangSmith. - **Installation**: Clone https://github.com/openlit/openlit or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ### Spanlens - **Fork Page**: [Spanlens Profile](https://caniforkit.com/fork/spanlens) - **Head-to-Head Comparison**: [LangSmith vs Spanlens](https://caniforkit.com/vs/langsmith-vs-spanlens) - **Official Website**: https://www.spanlens.io/ - **Source Code Repository**: https://github.com/spanlens/Spanlens - **License**: Open Source - **Runs On**: Self-host - **GitHub Stars**: 13 - **Maintenance Activity**: nov 2026 - **Supported Platforms**: web, self-hosted, docker to self-host - **Summary**: Drop-in observability platform for OpenAI, Anthropic, and Gemini that logs every request, tracks costs, traces agent workflows, and flags anomalies and PII. - **The Catch vs LangSmith**: Requires self-hosting setup, updates, and server maintenance compared to managed LangSmith. - **Installation**: Clone https://github.com/spanlens/Spanlens or deploy with Docker Compose - **Setup**: Deploy via Docker or binary release from GitHub and configure environment variables. - **Data Storage**: All application data and configuration live on your own server or local database. ## Frequently Asked Questions ### What is the best free alternative to LangSmith? The top free alternative to LangSmith is Langfuse (open source, Open Source). Langfuse provides tracing, evaluations, prompt management, and analytics to debug and improve LLM applications. Other popular LangSmith replacements include Arize Phoenix, OpenLLMetry, Helicone. ### How much does switching from LangSmith to a free alternative save? LangSmith starts at $35/month per seat ($420/year). Switching a 5-person team to a free alternative like Langfuse saves $2,100 per year in software subscription fees. ### What is the catch when switching away from LangSmith? While Langfuse replaces core LangSmith features without subscription fees, the real-world trade-off is: Requires self-hosting setup, updates, and server maintenance compared to managed LangSmith. ## Related - [analytics Software Category Hub](https://caniforkit.com/category/analytics) - [All Paid SaaS Alternatives Index](https://caniforkit.com/alternatives) - [Self-Hosted Software Directory](https://caniforkit.com/self-hosted) - [Homepage](https://caniforkit.com)