ERNIE 5.1

Baidu's flagship ERNIE 5.1, derived from ERNIE 5.0 by extracting an optimal sub-network from its elastic sub-model matrix — compressing total parameters to ~1/3 and active parameters to ~1/2 of ERNIE 5.0 while reaching leading performance at only ~6% of the pre-training compute of comparable models. A Mixture-of-Experts model trained with a disaggregated fully-asynchronous RL stack and a multi-teacher on-policy-distillation pipeline, tuned for agentic execution, reasoning, world knowledge, and creative writing. Vendor-reported results: 99.6 on AIME26 (with tools, second only to Gemini 3.1 Pro), GPQA and MMLU-Pro approaching leading closed models, surpassing DeepSeek-V4-Pro on τ³-bench and SpreadsheetBench-Verified, and ranking 1st among Chinese models / 4th globally (score 1223) on the LMArena Search Arena. Proprietary; served via ERNIE Bot, Baidu AI Studio, and the Qianfan platform.