Kimi K3 is second only to Fable 5 on AA-Briefcase， our agentic knowledge work benchmark， but costs more than Opus 4.8 to run while averaging nearly an hour per task
Last week @Kimi_Moonshot released Kimi K3， a 2.8T parameter model that scores 57 on the Artificial Analysis Intelligence Index， comparable to models such as Opus 4.8 and GPT-5.5. On AA-Briefcase， Kimi K3 scores an Elo of 1543， a +727 improvement over Kimi K2.6 and the second highest score recorded， behind only Claude Fable 5 （1574）
AA-Briefcase is our new proprietary benchmark for agentic knowledge work， testing models on a fully private dataset of realistic tasks across thousands of complex input files. Tasks require deliverables such as spreadsheets， presentations， and UI mock-ups， with performance combined into a single AA-Briefcase Elo based on correctness， analytical quality， and presentation quality
Key results for Kimi K3 on AA-Briefcase：
➤ Second only to Fable 5： Kimi K3 achieves an AA-Briefcase Elo of 1543， the second-highest score overall， ahead of GPT-5.6 Sol （max， 1501）， Claude Sonnet 5 （max， 1388）， and Claude Opus 4.8 （max， 1347）. This is a +727 improvement over the previous-generation Kimi K2.6 （816） and puts Kimi K3 only behind Fable 5
➤ Strong objective and analytical performance， with comparatively weaker presentation： Kimi K3 achieves a rubric pass rate of 51%， second only to Claude Fable 5 （56%） and ahead of Claude Sonnet 5 （max， 42.3%） and GPT-5.6 Sol （max， 41.8%）. It also records an analytical quality Elo of 1754， comparable to Claude Fable 5 （1744）. Presentation quality is comparatively weaker， with a Presentation Elo of 1471， below GPT-5.6 Sol （max， 1660） and Claude Opus 4.8 （max， 1492）