Baidu: ERNIE 4.5 21B A3B Thinking✓ Catalog verified
ERNIE-4.5-21B-A3B-Thinking is Baidu's upgraded lightweight MoE model, refined to boost reasoning depth and quality for top-tier performance in logical puzzles, math, science, coding, text generation, and expert-level academic benchmarks.
Overview
ERNIE-4.5-21B-A3B-Thinking is Baidu's upgraded lightweight MoE model, refined to boost reasoning depth and quality for top-tier performance in logical puzzles, math, science, coding, text generation, and expert-level academic benchmarks.
Access: available through the official Baidu API. Context window: 131K.
Specifications
| API identifier | baidu/ernie-4.5-21b-a3b-thinking |
| Provider | Baidu |
| Model type | Text LLM |
| Context window | 131K catalog |
| Input modalities | text |
| Output modalities | text |
| Released | Oct 9, 2025 |
| Moderated | No |
| Architecture modality | text->text |
API defaults
{
"top_p": 0.95,
"temperature": 0.6,
"frequency_penalty": null
}Pricing
Live pricing components for baidu/ernie-4.5-21b-a3b-thinking as published in the catalog.
| Pricing component | Raw unit price | Normalized | Unit |
|---|---|---|---|
| Prompt tokens | $7e-8 | $0.07 / 1M | Per input token |
| Completion tokens | $2.8e-7 | $0.28 / 1M | Per output token |
| Request fee | N/A | N/A | Per request |
| Image fee | N/A | N/A | Per image unit |
| Web search fee | N/A | N/A | Per search request |
Cost calculator
Estimate monthly spend from your own token volumes.
Estimated Total Cost
$0.09Calculated from current list pricing in the ModelsAtlas catalog.Capabilities
| Capability | Status | What it means |
|---|---|---|
| Visual Understanding | Not advertised | Image and document analysis support |
| Audio Processing | Not advertised | Speech and voice aligned flows |
| Tool Calling | Not advertised | Supports tools / function calling |
| Self-Hosting | Not advertised | Deploy outside managed APIs |
Capability signals
Directional signals derived from model metadata and capability tags — not official benchmark submissions.
Quick start
Call Baidu: ERNIE 4.5 21B A3B Thinking through an OpenAI-compatible client.
from openai import OpenAI
client = OpenAI(
base_url="https://openrouter.ai/api/v1",
api_key="YOUR_API_KEY"
)
response = client.chat.completions.create(
model="baidu/ernie-4.5-21b-a3b-thinking",
messages=[{"role": "user", "content": "Explain quantum physics."}]
)
print(response.choices[0].message.content)Alternatives
Closest models by context window from a different provider.
| Model | Provider | Context | Input /1M | Actions |
|---|---|---|---|---|
| AionLabs: Aion-1.0 | Aion Labs | 131K | $4.00 | View → |
| AionLabs: Aion-1.0-Mini | Aion Labs | 131K | $0.70 | View → |
Sources & attribution
Pricing and metadata are maintained in the ModelsAtlas catalog.
Frequently asked questions
How much does Baidu: ERNIE 4.5 21B A3B Thinking cost?
$0.07 per 1M input tokens and $0.28 per 1M output tokens on the official Baidu API.
What is the context window of Baidu: ERNIE 4.5 21B A3B Thinking?
Baidu: ERNIE 4.5 21B A3B Thinking supports up to 131K tokens of context.
Does Baidu: ERNIE 4.5 21B A3B Thinking support tool / function calling?
Baidu: ERNIE 4.5 21B A3B Thinking does not advertise first-class tool/function calling. Check vendor docs for the latest capabilities.
How do I access Baidu: ERNIE 4.5 21B A3B Thinking?
Use the official Baidu API with the model id `baidu/ernie-4.5-21b-a3b-thinking`. See the Quick start section above for code examples.