LightweightBaidu

ERNIE 4.5 21B

ERNIE 4.5 21B is Baidu's lightweight text-only model with a 120K token context window, designed for efficient Chinese and multilingual language tasks.

Context 120K
Tier Lightweight
Input from
$0.070 / 1M tokens
across 1 provider
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API Pricing

ProviderInput / 1MOutput / 1MUpdated
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OpenRouter
$0.070$0.2804/14/2026

Prices updated daily. Last check: 4/14/2026

Model Details

General

Creator
Baidu
Family
ERNIE
Tier
Lightweight
Context Window
120K
Modalities
Text

Capabilities

Tool Calling
No
Open Source
No
Aliases
ernie-4-5-21b-a3b-thinking

Strengths & Limitations

  • 120K token context window enables processing of long documents
  • 21B parameter size provides computational efficiency compared to larger models
  • Optimized for Chinese language understanding and generation
  • Lightweight tier positioning offers faster inference speeds
  • Part of Baidu's established ERNIE model family
  • Text-focused architecture without multimodal complexity
  • Suitable for high-volume text processing applications
  • No tool calling or function execution capabilities
  • Text-only modality lacks image or audio input support
  • Proprietary model with no open source availability
  • Smaller parameter count compared to flagship alternatives
  • Limited compared to newer frontier models in capability

Key Features

•120K token context window
•Text-only input and output
•21 billion parameter architecture
•Chinese language optimization
•Multilingual text processing
•Lightweight computational requirements
•Streaming text generation
•Batch processing support

About ERNIE 4.5 21B

ERNIE 4.5 21B is a lightweight model in Baidu's ERNIE family, positioning it as an efficient option below Baidu's flagship offerings. As a 21 billion parameter model, it balances computational efficiency with language understanding capabilities, particularly for Chinese language tasks where Baidu's training expertise is concentrated. The model supports a 120K token context window and operates as a text-only system without multimodal capabilities. It does not include tool calling functionality, focusing instead on core language understanding and generation tasks. The model's architecture reflects Baidu's approach to creating models optimized for Chinese language nuances while maintaining multilingual capabilities. ERNIE 4.5 21B serves applications requiring reliable language processing without the computational overhead of larger models. Its position as a lightweight option in the ERNIE family makes it suitable for scenarios where efficiency and cost-effectiveness are prioritized over maximum capability, particularly for Chinese language applications and moderate-complexity text processing tasks.

Common Use Cases

ERNIE 4.5 21B is well-suited for applications requiring efficient text processing at scale, particularly those involving Chinese language content. Its lightweight architecture makes it appropriate for high-volume document analysis, content summarization, translation tasks, and customer service applications where response speed and cost efficiency are important. The 120K context window enables processing of lengthy documents, research papers, or conversational histories without truncation. Organizations operating primarily in Chinese markets or requiring bilingual Chinese-English capabilities can leverage this model for content generation, text classification, and language understanding tasks where the computational efficiency of a 21B parameter model provides an optimal balance of capability and resource utilization.

Frequently Asked Questions

How much does ERNIE 4.5 21B cost per million tokens?

ERNIE 4.5 21B pricing varies by provider and pricing type (standard vs batch). Check the pricing table above for current rates across all providers.

What is ERNIE 4.5 21B best used for?

ERNIE 4.5 21B excels at Chinese language processing, document analysis with its 120K context window, and high-volume text generation tasks where computational efficiency is important. Its lightweight architecture makes it suitable for applications requiring fast response times and cost-effective operation.

Does ERNIE 4.5 21B support function calling or tool use?

No, ERNIE 4.5 21B does not include tool calling capabilities. It focuses on text-only language understanding and generation tasks without function execution or structured output features.