ERNIE 5.1
ernie-5.1
About
ERNIE 5.1 is Baidu's fifth-generation flagship language model, officially released May 9, 2026. Achieved via disaggregated fully-asynchronous reinforcement learning and scaled agentic post-training, it delivers leading performance at approximately 6% of the pre-training compute cost of comparable models — with roughly one-third the total parameters and half the active parameters of ERNIE 5.0. ERNIE 5.1 ranks #4 globally and #1 among Chinese models on the LMArena Search leaderboard (score: 1,223), with standout performance in legal reasoning, mathematics (AIME26: 99.6), and business domains. API model ID: ernie-5.1. Context: 128K tokens; max output: 65,536 tokens.
ERNIE 5.1 has a 128K-token context window.
ERNIE 5.1 input tokens at $0.59/1M, output at $2.65/1M.
Capabilities
Providers(1)
| Provider | Input (per 1M) | Output (per 1M) | Type | |
|---|---|---|---|---|
| Baidu Qianfan | $0.59 | $2.65 | Serverless |
Benchmark Scores(1)
| Benchmark | Score | Version | Source |
|---|---|---|---|
| Chatbot Arena | 1476.0 | Arena Elo | https://ernie.baidu.com/blog/posts/ernie-5.1-0508-release/ |
