> For the complete documentation index, see [/llms.txt](/llms.txt).

# Solar Pro 2

> Source: /docs/models/solar-pro-2

> Deprecation notice
>
> Solar Pro 2 (the `solar-pro2` alias and all of its versions) will be fully deprecated on **October 30, 2026 (KST)**. Requests naming it will return an error after that date. Please migrate to [Solar Pro 4](/docs/models/solar-pro-4) before then.

Advanced reasoning, tool use, and multilingual support

[Compare](/docs/models/compare/generative-intelligence) · [Try in Playground](/playground/chat)

- **Intelligence**: 3 (Higher)
- **Speed**: 4 (Fast)
- **Price**: $0.15/1M tokens (Input Token)
- **Price**: $0.6/1M tokens (Output Token)
- **Price**: $0.015/1M tokens (Cached Token)

A high-performance model from Upstage that supports both Chat and Reasoning modes, allowing users to tailor performance based on task complexity. [Reasoning](/docs/capabilities/generate/reasoning) mode provides structured, multi-step thinking for complex tasks, while [Chat](/docs/capabilities/generate/chat) mode delivers fast, direct responses for simpler queries. By supporting both modes in a single model, this design achieves an optimal balance of speed, accuracy, and resource efficiency for diverse use cases. [Learn more](https://www.upstage.ai/blog/en/experience-stronger-korean-fluency-in-the-new-solar-llms?utm_medium=console&utm_source=docs-models)

- 65,536 context length
- 31B parameters
- Mar, 2025 training data cut-off
- Reasoning mode available

## Languages

- English: Input and output
- Korean: Input and output
- Japanese: Input and output

## Capabilities

- [Chat](/docs/capabilities/generate/chat): Supported
- [Structured outputs](/docs/capabilities/generate/structured-outputs): Supported
- [Tool calling](/docs/capabilities/generate/tool-calling): Supported
- [Reasoning](/docs/capabilities/generate/reasoning): Supported

## Available Platforms

- Upstage Console
- [AWS Marketplace](https://aws.amazon.com/marketplace/seller-profile?id=seller-56j52of2hnuzo)
- [On-premises](https://www.upstage.ai/contact-us?utm_medium=console&utm_source=docs-models&utm_content=text-link)

## Versions

### solar-pro2-251215 (Alias: solar-pro2)

Released on 2025-12-15

Training data cut-off: Mar, 2025

This release includes the following updates.

- Improved inference efficiency through optimized quantization.
- Fixed an issue where parallel tool calls could result in incorrect streaming chunk ordering.
- Resolved an issue where reasoning was not properly triggered when using guided decoding.
- Fixed response_format handling to work correctly with reasoning mode.
- Added support for NVIDIA Blackwell and ARM64 architectures.

[Learn more](https://www.upstage.ai/blog/en/solar-pro-2-launch?utm_medium=console&utm_source=docs-models)

- Available platforms: Upstage Console, [On-premises](https://www.upstage.ai/contact-us?utm_medium=console&utm_source=docs-models&utm_content=text-link)

### solar-pro2-250909

Released on 2025-09-09

Training data cut-off: Mar, 2025

This release includes the following updates.

- Resolved an issue where the model's response could occasionally repeat itself when processing tool calls.

[Learn more](https://www.upstage.ai/blog/en/solar-pro-2-launch?utm_medium=console&utm_source=docs-models)

- Available platforms: [On-premises](https://www.upstage.ai/contact-us?utm_medium=console&utm_source=docs-models&utm_content=text-link)

### solar-pro2-250710

Released on 2025-07-10

Training data cut-off: Mar, 2025

A high-performance model from Upstage that supports both Chat and Reasoning modes, allowing users to tailor performance based on task complexity. [Reasoning](/docs/capabilities/generate/reasoning) mode provides structured, multi-step thinking for complex tasks, while [Chat](/docs/capabilities/generate/chat) mode delivers fast, direct responses for simpler queries. By supporting both modes in a single model, this design achieves an optimal balance of speed, accuracy, and resource efficiency for diverse use cases. [Learn more](https://www.upstage.ai/blog/en/solar-pro-2-launch?utm_medium=console&utm_source=docs-models)

- Available platforms: [On-premises](https://www.upstage.ai/contact-us?utm_medium=console&utm_source=docs-models&utm_content=text-link)

## API privacy

Data not collected

Upstage does not collect any data from this API

1. API input data is not used for model training.
2. API input data is not stored, unless required for service delivery and explicitly stated.

Free

Chat with Solar LLMs in the Playground!

✓ Chat with Solar

✓ Configure & run in browser

✓ No API key needed - free to try

[Try it in the Playground](/playground/chat)