Comparison

LM Evaluation Harness vs OpenAI Evals

On the evidence we track, LM Evaluation Harness leads this comparison with a composite score of 48/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.

Machine formatsMarkdownJSONGraphQLMarkdown is open. JSON and GraphQL need a free key.
★LM Evaluation Harness48
OpenAI Evals40
Score
vioscaleAI score
LM Evaluation Harness48 / 100low · 35%
OpenAI Evals40 / 100low · 22%
Pricing
Free tier
LM Evaluation Harness✓
OpenAI Evals✓
Model
LM Evaluation Harnessopen_source
OpenAI Evalsopen_source
Price level
LM Evaluation Harnessfree
OpenAI Evalsfree
Transparent
LM Evaluation Harness✓
OpenAI Evals✓
Integrations
Count
LM Evaluation Harness5
OpenAI Evals3
Adoption
Dependent repos
LM Evaluation Harness252
OpenAI Evals1
Github stars
LM Evaluation Harness14,221
OpenAI Evals19,604
Activity
Commits last 30d
LM Evaluation Harness57
OpenAI Evals0
Release
Cadence days
LM Evaluation Harness72
OpenAI Evals–
History
LM Evaluation Harness19 items
OpenAI Evals–
License
Spdx
LM Evaluation HarnessMIT
OpenAI Evals–
Language
Primary
LM Evaluation HarnessPython
OpenAI EvalsPython
Content
Faq
LM Evaluation Harness6 items
OpenAI Evals5 items

Capabilities

Feature-by-feature on the axes that matter for ai evals testing. “-” means undocumented, not absent.

Capabilities
Architecture model
LM Evaluation HarnessOpen source CLI
OpenAI EvalsOpen source CLI
LLM as a judge prompt grading framework
LM Evaluation Harness-
OpenAI Evals✓
Specialized rag metrics faithfulness context relevance
LM Evaluation Harness-
OpenAI Evals-
Deterministic regex and json schema assertions
LM Evaluation Harness-
OpenAI Evals✓
Synthetic test dataset generation from documents
LM Evaluation Harness-
OpenAI Evals✓
Ci cd github actions pipeline blocking gates
LM Evaluation Harness-
OpenAI Evals✓
Red teaming and adversarial vulnerability scanning
LM Evaluation Harness-
OpenAI Evals-
Multi model side by side ab regression testing
LM Evaluation Harness✓
OpenAI Evals-
Human in the loop hitl annotation UI
LM Evaluation Harness-
OpenAI Evals-
Dashboard analytics for metric drift over time
LM Evaluation Harness-
OpenAI Evals-
SOC2 type ii
LM Evaluation Harness-
OpenAI Evals-
Mit or apache permissive oss license
LM Evaluation Harness-
OpenAI Evals✓
Pricing model
LM Evaluation HarnessFree open source
OpenAI EvalsFree open source

What each one is

The product in its own terms, so the numbers below have context.

LM Evaluation Harness

Leader

A framework for conducting few-shot evaluation of language models against various tasks and benchmarks. Supports multiple model backends, custom evaluation metrics, and extensible task definitions for assessing model capabilities and performance.

Independently observed

OpenAI Evals

An open-source framework providing a registry of evaluation tests for LLMs, with the ability to create custom evaluations and test models against your own data through code-free configuration.

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

LM Evaluation Harness

Leader
Open sourceFree tier
as of verify ↗

OpenAI Evals

Open sourceFree tier
as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
Web
LM Evaluation Harness✗
OpenAI Evals✓
macOS
LM Evaluation Harness✓
OpenAI Evals✗
Windows
LM Evaluation Harness✓
OpenAI Evals✗
Linux
LM Evaluation Harness✓
OpenAI Evals✗
CLI
LM Evaluation Harness✓
OpenAI Evals✓
Deployment
Cloud / SaaS
LM Evaluation Harness✗
OpenAI Evals✓
Self-hosted
LM Evaluation Harness✓
OpenAI Evals✓

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

In common (1)
  • GitHub

LM Evaluation Harness

Leader
5 total - 4 not shared
  • Hugging Face
  • PyTorch
  • VLLM
  • OpenAI-compliant APIs
Independently observed

OpenAI Evals

3 total - 2 not shared
  • OpenAI API
  • Snowflake
Independently observed
Still deciding?

LM Evaluation Harness or OpenAI Evals: which one depends on you

A composite score cannot know your constraints. Describe them and both get re-weighted against what you actually need, with the evidence behind every position.

Free to run, no account needed to start. How the evaluation works

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.