{"slug":"lm-evaluation-harness","name":"lm-evaluation-harness","domain":"github.com","verdict":"As of 2026-07-13, ChatGPT, Claude, Gemini, Grok collectively rank lm-evaluation-harness #5 of 8 for open-source llm eval framework. Source: https://modelsagree.com/product/lm-evaluation-harness (modelsagree.com, CC BY 4.0).","best_rank":5,"categories":1,"brief":{"category":"best-llm-eval-framework-open-source","title":"Best open-source LLM eval framework","rank":5,"of":8,"top":"DeepEval","day":"2026-07-19","why":[{"t":"standard for reproducible model benchmarking","m":["ChatGPT","Claude"],"q":"The standard for reproducible model benchmarking"},{"t":"hundreds of academic tasks","m":["ChatGPT","Claude"],"q":"hundreds of academic tasks"},{"t":"extensive model backend support","m":["ChatGPT","Claude"],"q":"backend support from Hugging Face to vLLM"},{"t":"broad research adoption","m":["ChatGPT","Claude"],"q":"broad research adoption"}],"gap":[{"t":"application-level eval toolkit","m":["Claude","Gemini","Grok","ChatGPT"],"q":"The most complete application-level eval toolkit in open source"},{"t":"RAG and agent evaluation","m":["Claude","Gemini","Grok","ChatGPT"],"q":"RAG and agent evaluation"},{"t":"CI/CD integration","m":["Claude","Gemini","Grok","ChatGPT"],"q":"synthetic dataset generation, and CI/CD integration"}],"fix":[{"t":"evaluation of tool-using agents","m":["ChatGPT","Claude"],"q":"Add first-class evaluation of tool-using agents and complete LLM applications"},{"t":"judging RAG pipelines and applications","m":["ChatGPT","Claude"],"q":"useless for judging RAG pipelines, agents, or product-specific quality"}]},"entries":[{"slug":"best-llm-eval-framework-open-source","title":"Best open-source LLM eval framework","rank":5,"of":8,"score":6,"appearances":2,"modelRanks":{"ChatGPT":3,"Claude":3},"reason":"The standard for reproducible model benchmarking, with a huge task catalog, extensive local and hosted model backends, efficient batching, few-shot controls, and broad research adoption","reasons":[{"model":"ChatGPT","reason":"The standard for reproducible model benchmarking, with a huge task catalog, extensive local and hosted model backends, efficient batching, few-shot controls, and broad research adoption"},{"model":"Claude","reason":"EleutherAI's harness remains the de facto standard for model-level benchmarking — hundreds of academic tasks, reproducible few-shot protocols, backend support from Hugging Face to vLLM, and it powers major public leaderboards; ranked assuming practitioners also need to compare foundation models, not just app outputs."}],"fixes":[{"model":"ChatGPT","fix":"Add first-class evaluation of tool-using agents and complete LLM applications"},{"model":"Claude","fix":"It evaluates models on static benchmarks, not your application — useless for judging RAG pipelines, agents, or product-specific quality, and benchmark contamination limits what scores mean."}],"updated":"2026-07-13","rank_history":{"days":["2026-07-12","2026-07-13"],"ranks":[5,5]},"api":"https://modelsagree.com/api/v1/best/best-llm-eval-framework-open-source.json"}],"page":"https://modelsagree.com/product/lm-evaluation-harness","check":"https://modelsagree.com/check?q=lm-evaluation-harness","updated":"2026-08-10T18:18:45.051Z","attribution":"modelsagree.com, CC BY 4.0"}