Baidu Releases ERNIE 5.1 with Pre-Training Cost at Just 6% of Industry Peers

Baidu officially released ERNIE 5.1 on May 9, 2026, a foundation model achieving leading performance at only 6% of the pre-training cost of comparable models. Using Baidu's Once-for-All elastic training framework, ERNIE 5.1 compresses total parameters to ~1/3 of ERNIE 5.0 and active parameters to ~1/2. On the LMArena Search leaderboard, ERNIE 5.1 scored 1,223, ranking 4th globally and 1st among Chinese models, surpassing DeepSeek-V4-Pro. On AIME26 with tool use, it scores 99.6 — second only to Gemini 3.1 Pro. Agentic capabilities on tau^3-bench and SpreadsheetBench-Verified surpass DeepSeek-V4-Pro. The model is available on Baidu's Qianfan Model Square and ERNIE Bot website.