LMArena Agent Arena

LMArena · agent-2026-08-27-51d09b2e834b · Outcome-based measurements from real LMArena agent sessions.

Source
#1Claude Opus 5Anthropic12.73score16,214Claude Opus 5 (Max); 95% CI [10.76557334, 14.69307729]; sessions 16214; observations 1961892; rank 2unknownOriginal sourcewinner eligibleThird-party benchmark
#2Claude Fable 5Anthropic11.70score33,805Claude Fable 5 (High); 95% CI [10.07161960, 13.32098598]; sessions 33805; observations 1575929; rank 3unknownOriginal sourcewinner eligibleThird-party benchmark
#3GPT-5.6 SolOpenAI10.24score27,506GPT 5.6 Sol (xHigh); 95% CI [8.75169248, 11.72000008]; sessions 27506; observations 2731648; rank 4unknownOriginal sourcewinner eligibleThird-party benchmark
#4Claude Sonnet 5Anthropic7.65score26,480Claude Sonnet 5 (High); 95% CI [5.40721597, 9.90155163]; sessions 26480; observations 2580319; rank 8unknownOriginal sourcewinner eligibleThird-party benchmark
#5GPT-5.6 LunaOpenAI3.41score13,855GPT 5.6 Luna (xHigh); 95% CI [2.03069485, 4.79820702]; sessions 13855; observations 970830; rank 21unknownOriginal sourcewinner eligibleThird-party benchmark
#6GPT-5.6 TerraOpenAI3.00score15,773GPT 5.6 Terra (xHigh); 95% CI [1.81214534, 4.19675164]; sessions 15773; observations 867221; rank 23unknownOriginal sourcewinner eligibleThird-party benchmark
#7Hy3Tencent-1.19score22,177Hy3; 95% CI [-2.46898520, 0.08511072]; sessions 22177; observations 762738; rank 35unknownOriginal sourcewinner eligibleThird-party benchmark
#8Mistral-Medium-3.5-128BMistral AI-5.76score6,727Mistral Medium 3.5; 95% CI [-7.57289629, -3.94108228]; sessions 6727; observations 205359; rank 43unknownOriginal sourcewinner eligibleThird-party benchmark

8 models ranked by the best winner-eligible current-version score when available, otherwise the best publisher-artifact score; highest first. Observed Aug 29, 2026.

Ranking protocol

outcome score · score. Each model appears once; verified winner-eligible runs take precedence, and missing models are not imputed.

Acquisition coverage

8 published models from 54 source rows; 46 source identities remain quarantined.

Primary evidence

Publisher artifacts

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