What is the best free alternative to Laminar?
Arize Phoenix is the closest free alternative to Laminar: same LLM Eval & Observability sub-category, and it is free. Fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported)
Best free Laminar alternatives
Looking for a free alternative to Laminar? Here are 9 llm eval & observability worth trying — 9 with a free tier. Laminar itself is free.
| Tool | Laminar (you searched) | Arize Phoenix | Google Stax | DeepEval |
|---|---|---|---|---|
| Pricing | free | free | free | free |
| Best for | Open-source observability and evals platform for AI agents (Apache-2.0) | Fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported) | Build evals with human raters or LLM autoraters on your own data | Open-source LLM evaluation framework with pytest-style tests and 50+ metrics |
| Visit | Open ↗ | Open ↗ | Open ↗ | Open ↗ |
Laminar alternatives — straight answers
Are there free Laminar alternatives?
Yes — 9 of the 9 alternatives listed here are free or freemium: Arize Phoenix, Google Stax, DeepEval, EleutherAI LM Evaluation Harness, OpenLLMetry (Traceloop). None of them are paid-only.
Is Laminar free?
Laminar is free. There is no paid plan attached to it in the catalog.
How were these Laminar alternatives chosen?
They are the other tools in LLM Eval & Observability, then the rest of AI Models & Local Execution, ordered free tiers first and capped at 9. There is no sponsorship and no paid placement in that ordering — only the pricing tier decides.
All Laminar alternatives
Browse LLM Eval & Observability →Arize Phoenix
LLM Eval & Observability
✦ WhyA Laminar alternative — Fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported).
- Fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported)
- Combines tracing, evals, datasets, experiments and prompt playground in one local-first tool
- AI engineering agent (PXI) built in for automated troubleshooting of traces
✦ WhyA Laminar alternative — Build evals with human raters or LLM autoraters on your own data.
- Build evals with human raters or LLM autoraters on your own data
- Compare models and prompts on quality, latency and token cost
- Prebuilt and custom evaluators
✦ WhyA Laminar alternative — Open-source LLM evaluation framework with pytest-style tests and 50+ metrics.
- Open-source LLM evaluation framework with pytest-style tests and 50+ metrics
- RAG, agent and conversational metrics; red-teaming module
- Apache-2.0; optional Confident AI cloud has a free tier
✦ WhyA Laminar alternative — Standard open framework for running hundreds of benchmarks (MMLU, GSM8K and more) against any LLM.
- Standard open framework for running hundreds of benchmarks (MMLU, GSM8K and more) against any LLM
- Backs the Hugging Face Open LLM evaluations
- MIT licensed CLI and Python library
✦ WhyA Laminar alternative — OpenTelemetry-based instrumentation for LLM calls, vector DBs and frameworks.
- OpenTelemetry-based instrumentation for LLM calls, vector DBs and frameworks
- Ships traces to Datadog, Grafana, Honeycomb or any OTel backend
- Apache-2.0
Langfuse
LLM Eval & Observability
✦ WhyA Laminar alternative — Fully open-source and self-hostable for free via Docker Compose/Kubernetes, not just a hosted SaaS.
- Fully open-source and self-hostable for free via Docker Compose/Kubernetes, not just a hosted SaaS
- Hobby cloud plan is free with no credit card, 50k observability units/month
- Combines tracing, prompt management, evals and datasets in one open platform
Braintrust
LLM Eval & Observability
✦ WhyA Laminar alternative — Free Starter plan ships model credits and scored evals with no card required.
- Free Starter plan ships model credits and scored evals with no card required
- Unlimited users/projects/datasets/playgrounds even on the free tier
- Built-in playground for side-by-side prompt/model comparison against production traces
Promptfoo
LLM Eval & Observability
✦ WhyA Laminar alternative — Open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI.
- Open-source CLI/library for evaluating prompts, models and RAG pipelines side by side, runs in CI
- Automated red-teaming to surface prompt injection, jailbreak and data-leak vulnerabilities
- 300,000+ user community with an enterprise tier for teams needing hosted guardrails
W&B Weave
LLM Eval & Observability
✦ WhyA Laminar alternative — Agent-native tracing model with sessions, steps, tools and sub-agents as first-class concepts (not generic spans).
- Agent-native tracing model with sessions, steps, tools and sub-agents as first-class concepts (not generic spans)
- Pre-built safety/quality scorers for toxicity, bias, PII and hallucination detection out of the box
- Built on Weights & Biases' existing ML-experiment infrastructure, useful for teams already on W&B