Best free DeepEval alternatives

Looking for a free alternative to DeepEval? Here are 9 llm eval & observability worth trying — 9 with a free tier. DeepEval itself is free.

ToolDeepEval (you searched)Arize PhoenixGoogle StaxEleutherAI LM Evaluation Harness
Pricingfreefreefreefree
Best forOpen-source LLM evaluation framework with pytest-style tests and 50+ metricsFully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported)Build evals with human raters or LLM autoraters on your own dataStandard open framework for running hundreds of benchmarks (MMLU, GSM8K and more) against any LLM
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DeepEval alternatives — straight answers

What is the best free alternative to DeepEval?

Arize Phoenix is the closest free alternative to DeepEval: same LLM Eval & Observability sub-category, and it is free. Fully open-source, self-hostable with zero setup via `uvx` (pip/conda also supported)

Are there free DeepEval alternatives?

Yes — 9 of the 9 alternatives listed here are free or freemium: Arize Phoenix, Google Stax, EleutherAI LM Evaluation Harness, OpenLLMetry (Traceloop), Laminar. None of them are paid-only.

Is DeepEval free?

DeepEval is free. There is no paid plan attached to it in the catalog.

How were these DeepEval 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 DeepEval alternatives

Browse LLM Eval & Observability →

Arize Phoenix

LLM Eval & Observability
free

✦ WhyA DeepEval 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
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Google Stax

LLM Eval & Observability
freeNew

✦ WhyA DeepEval 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
Visit

EleutherAI LM Evaluation Harness

LLM Eval & Observability
freeNew

✦ WhyA DeepEval 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
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OpenLLMetry (Traceloop)

LLM Eval & Observability
freeNew

✦ WhyA DeepEval 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
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Laminar

LLM Eval & Observability
freeNew

✦ WhyA DeepEval alternative — Open-source observability and evals platform for AI agents (Apache-2.0).

  • Open-source observability and evals platform for AI agents (Apache-2.0)
  • Traces, session replay for browser agents and evaluations
  • Self-hostable
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Langfuse

LLM Eval & Observability
freemium

✦ WhyA DeepEval 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
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Braintrust

LLM Eval & Observability
freemium

✦ WhyA DeepEval 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
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Promptfoo

LLM Eval & Observability
freemium

✦ WhyA DeepEval 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
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W&B Weave

LLM Eval & Observability
freemium

✦ WhyA DeepEval 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
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DeepEval head-to-head

DeepEval vs Arize PhoenixDeepEval vs Google StaxDeepEval vs EleutherAI LM Evaluation HarnessDeepEval vs OpenLLMetry (Traceloop)DeepEval vs LaminarDeepEval vs LangfuseDeepEval vs BraintrustDeepEval vs Promptfoo