Baidu releases ERNIE 5.1, a third the size of ERNIE 5.0, claiming 6% of the usual pre-training cost

Baidu/ERNIE 5

ERNIE 5.1 has about a third of ERNIE 5.0's total parameters and half its active ones. Baidu trained a family of model sizes in one run and says pre-training cost about 6% of comparable models. It placed 4th on LMArena's search leaderboard, but the weights are closed, so claims can't be checked independently.

• Search Arena: 1,223 points, 4th globally and first among Chinese models.
• Text Arena preview: 13th place with 1,476 points.
• Available at ernie.baidu.com and through Baidu's cloud API; Baidu said it was rolling out on more than ten creative and agent platforms in China.
• Shown to developers at Baidu's Create 2026 conference in Beijing on May 13-14.