Free LangSmith Alternatives (2026)
LangSmith: free Developer plan: 5k traces per month (checked ); paid plans start at $39 a month. The top free LangSmith alternatives we've verified are Langfuse (free plan), Braintrust (free plan) and Arize Phoenix (self-host), all checked . All 4 picks below are free for at least a week. LangSmith — Observability, evals and deployment for LLM agents. Below are eligible free alternatives among LLM observability and eval platforms.
4 free alternatives
Evals and observability platform for AI products. Best for AI engineers. Key features: Tracing; Evals; Playgrounds.
Free forever, Free plan for evals and logging
Free accountTry
Open-source LLM tracing and evaluation. Best for AI engineers. Key features: Tracing; Evaluations; Experiments.
Free forever, Open-source and free cloud tier
Self-hostTry
- Kind of free
- Free plan
- Checked
- 2026-11-12
- What's free
- Free Hobby plan; open source self-host
- Kind of free
- Free plan
- Checked
- 2026-11-12
- What's free
- Free plan for evals and logging
- Kind of free
- Self-host
- Checked
- 2026-11-12
- What's free
- Open-source and free cloud tier
- Kind of free
- Free plan
- Checked
- 2026-11-12
- What's free
- Monthly requests
Is LangSmith free?
LangSmith — Free plan: Free Developer plan: 5k traces per month. Verified on 2026-11-12.
FAQ
- Which free LangSmith alternatives are free forever?
- All 4 here have a free plan with no end date: Langfuse, Braintrust, Arize Phoenix and 1 more. Each listing shows its free limits and the day we checked them.
- Are any free LangSmith alternatives open source?
- Yes: Arize Phoenix is open source and free to run yourself.
- How do you check these free plans?
- We read each maker's own pricing page and note the day we checked; the newest check on this page is 12 Nov 2026. Rank follows our published rules: paid placements are always labelled, and payment can't buy rank.
