ERNIE 5.1
ERNIE 5.1 is worth evaluating for rag, agents, and long context when its provider route and context window match the workload.
Use it for
- Teams evaluating rag, agents, and long context
- Workloads that can use a 128k context window
- Buyers comparing 1 tracked provider route
Do not use it for
- Vision or document-understanding workloads
- Family
- ERNIE 5
- Released
- 2026-05-09
- Context
- 128k
- Max output
- 65,536
- Openness
- Proprietary
- License
- ProprietaryCommercial use: conditional
- Weights
- Not released
- Code
- Unknown
Cheapest of 1 route · Baidu Qianfan
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.
Top use-case fit: coding, agents, and build tasks
RAG
Included by capability and metadata signals in the decision map.
Agents
Included by capability and metadata signals in the decision map.
Long context
Included by capability and metadata signals in the decision map.
Provider price ladder
Compare API pricing across 1 providers for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Route |
|---|---|---|---|
| Baidu Qianfan | $0.590 | $2.65 | Serverless |
Capabilities
Benchmark peer barsfor Classification
Benchmark scores(3)
| Benchmark | Score | Version | Evaluation | Source |
|---|---|---|---|---|
| Chatbot Arena | 1476.0 | Arena EloObserved 2026-05-12 | — | Source |
| MMLU PRO | 85.6 | —Observed 2026-05-09 | — | Source |
| Google-Proof Q&A | 82.1 | —Observed 2026-05-09 | — | Source |
Migration checks
No linked migration route is available for this model yet.
Rankings & picks(2)
Cheapest of 1 route · Baidu Qianfan