Best AI LLM Evaluation Tools in 2026
Updated
In short: Vellum is ranked #1 of 30 as of 3 October 2026, ahead of Weights & Biases and Opik. The best-ranked option with a free plan is Weights & Biases. The lowest first paid tier on this page is Opik at $19/mo.
Evaluating language-model tools starts with what you need to assess: outputs, prompts, or safety behavior. The ranked entries begin with DeepEval, Opik, and Langfuse. Compare evaluation methods, model support, and safety evaluations to understand the kinds of assessment covered. Prompt versioning can help you weigh tools when tracking prompt changes matters; API access and deployment provide additional comparison points for fitting a tool into a workflow. Free-plan availability and starting paid prices bring access and cost into the picture. Consider the evaluation tasks you have in mind, then compare them with the listed features and ranking order.
30 AI LLM evaluation tools ranked on what their makers publish — plans and prices, free tiers, platforms and the facts on their own pages.
Recognised 40% · Phone app 26% · Documented 20% · Free plan 14% of the score
- 1 Vellum iPhone + Android RecognisedPhone appDocumentedFree plan 7.9$30/mo
- 2 Weights & Biases iPhone only RecognisedPhone appDocumentedFree plan 7.9$60/mo
- 3 Opik No phone app RecognisedPhone appDocumentedFree plan 6.4$19/mo
- 4 Braintrust No phone app RecognisedPhone appDocumentedFree plan 6.3$249/mo
- 5 Confident AI No phone app RecognisedPhone appDocumentedFree plan 6.3$200/mo
- 6 DeepEval No phone app RecognisedPhone appDocumentedFree plan 6.3Free Safety evaluations: Yes
- 7 Evidently AI No phone app RecognisedPhone appDocumentedFree plan 6.3$80/mo
- 8 Galileo No phone app RecognisedPhone appDocumentedFree plan 6.3$100/mo
- 9 Giskard No phone app RecognisedPhone appDocumentedFree plan 6.3Free
- 10 Langfuse No phone app RecognisedPhone appDocumentedFree plan 6.3$29/mo
- 11 Maxim AI No phone app RecognisedPhone appDocumentedFree plan 6.3$29/mo
- 12 NVIDIA NeMo Evaluator No phone app RecognisedPhone appDocumentedFree plan 6.3Free Evaluation methods: Built-in benchmarks, exact match, fuzzy match, multiple-choice regex, answer-line, numeric match, code sandbox, LLM-as-judge, JSON-schema validation, regression comparison, quality gatesModel support: OpenAI-compatible model endpoints, NVIDIA API Catalog, vLLM, NIM, local vLLM, SGLang, TensorRT-LLM, vision-language modelsSafety evaluations: Yes
- 13 Promptfoo No phone app RecognisedPhone appDocumentedFree plan 6.3Free
- 14 Rhesis AI No phone app RecognisedPhone appDocumentedFree plan 6.3Free Evaluation methods: offline evaluation, online trace metrics, LLM-as-a-judge, custom metrics, single-turn testing, multi-turn testing, adversarial red-teamingModel support: OpenAI, Anthropic, Google Gemini, Azure OpenAI, Mistral, Cohere, Groq, Together AI, Perplexity, Replicate, Ollama, vLLM, LiteLLM ProxySafety evaluations: Yes
- 15 OpenAI Evals No phone app RecognisedPhone appDocumentedFree plan 5.9 Evaluation methods: basic exact/match evaluations, model-graded evaluations, custom evaluation logic, academic benchmarks, meta-evaluationsModel support: OpenAI API models and custom CompletionFunction implementationsSafety evaluations: Yes
- 16 Pydantic Evals No phone app RecognisedPhone appDocumentedFree plan 5.9 Evaluation methods: Deterministic checks; custom evaluators; LLM judges; G-Eval; performance checks; report evaluators; span-based evaluation; agentic trajectory evaluationModel support: OpenAI; Anthropic; Gemini; xAI; Bedrock; Cerebras; Cohere; Groq; Hugging Face; Mistral; OpenRouter; and other listed Pydantic AI providersSafety evaluations: Yes
- 17 UpTrain No phone app RecognisedPhone appDocumentedFree plan 5.9 Evaluation methods: preconfigured checks; custom prompt evaluations; custom Python evaluations; model-graded evaluations; classification; chain-of-thought classification; regression testing; experimentsModel support: OpenAI; Azure; Claude; Mistral; Together AI; Anyscale; Ollama; Hugging Face; Replicate; custom endpointsSafety evaluations: Yes
- 18 Parler-TTS No phone app RecognisedPhone appDocumentedFree plan 5.3
- 19 LangSmith No phone app RecognisedPhone appDocumentedFree plan 5.2
- 20 OpenCompass No phone app RecognisedPhone appDocumentedFree plan 5.2 Evaluation methods: objective; subjective; discriminative; generative; LLM-as-a-judgeModel support: Hugging Face models; API-based models; custom models; OpenAI; Anthropic; Gemini; Qwen; GLM; DeepSeekSafety evaluations: Yes
- 21 Ragas No phone app RecognisedPhone appDocumentedFree plan 5.2
- 22 HELM No phone app RecognisedPhone appDocumentedFree plan 5.1
- 23 HoneyHive No phone app RecognisedPhone appDocumentedFree plan 5.1
- 24 Inspect AI No phone app RecognisedPhone appDocumentedFree plan 5.1
- 25 LangWatch No phone app RecognisedPhone appDocumentedFree plan 5.1
Is your app on this list?
Numbered spots on this list can be sponsored. They are labelled, and the editorial order and scores never change for payment.
Questions about this list
Which AI LLM evaluation tool is ranked first on Samsung Mobile US Press?
Vellum is ranked #1 of 30 with a score of 7.9. Weights & Biases is second and Opik third.
How many of these have a free plan?
14 of the 25 on this page publish a free plan on their own pricing pages.
Which is the cheapest paid option?
On this page, Opik has the lowest first paid tier we found: $19/mo.
How is this list ranked?
Ranked mobile-first: a phone app alongside the web or desktop product, a free tier and the depth of its documentation. Paid placements never change a rank.