# LangSmith

Tracing, evaluation datasets and prompt playground for LLM apps and agents. LangSmith is freemium — a usable free tier with paid plans above it, at langchain.com.

## Facts

- **Pricing tier:** Free tier + paid
- **Works on:** Web, API
- **Works in browser:** Yes

## Capabilities

- Tracing, evaluation datasets and prompt playground for LLM apps and agents
- Developer plan is free with 5k base traces a month and one seat
- Framework-agnostic, works beyond LangChain

## FAQ

### What is LangSmith?

LangSmith is listed under LLM Eval & Observability, in the AI Models & Local Execution category on Flocci AI Tools. Tracing, evaluation datasets and prompt playground for LLM apps and agents. It is freemium — a usable free tier with paid plans above it, and it lives at langchain.com.

### Is LangSmith free?

LangSmith is freemium: there is a free tier you can work in and paid plans above it. It is one of 429 freemium tools in the catalog, all labelled the same way so you are never surprised by a paywall.

### Can I use LangSmith in a browser, or is there an app?

LangSmith works in a normal browser tab with no install. It is available on the web and an API.

### What can LangSmith do?

LangSmith does 3 things the catalog singles out: Tracing, evaluation datasets and prompt playground for llm apps and agents; developer plan is free with 5k base traces a month and one seat; framework-agnostic, works beyond langchain.

### What is the best free alternative to LangSmith?

Arize Phoenix is the closest free alternative: it sits in the same LLM Eval & Observability sub-category and is free. Google Stax, Laminar and DeepEval also start free. The full list is on the alternatives page.

## Related

- [LangSmith alternatives](https://aitools.flocci.in/alternatives/langsmith)
- [LLM Eval & Observability](https://aitools.flocci.in/category/ai-models-local-execution/llm-eval-observability)
- [Best free LLM evaluation and observability tools](https://aitools.flocci.in/best/best-llm-eval-observability)
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Source: Flocci AI Tools — https://aitools.flocci.in/tool/langsmith

Facts last verified: October 2026