# Qwen3.5 9B Base

> Qwen3.5 9B Base is an open-weight language model from Alibaba (Qwen), released on 26 Feb 2026. It accepts text and generates text, with a 66K-token context window and up to 66K output tokens per response.

Source page: https://www.aimodel.directory/models/qwen3-5-9b-base
Last verified: 21 Oct 2026

## Specifications

- **Developer:** Alibaba (Qwen)
- **Release date:** 26 Feb 2026 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Status:** Generally available (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Weights:** Open weights (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Context window:** 66K (65,536 tokens) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Max output:** 66K tokens (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Input:** Text (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Output:** Text (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Reasoning mode:** No (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)
- **Tool calling:** No (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/thinkingmachines/models/Qwen/Qwen3.5-9B-Base.toml)

## API pricing (USD per 1M tokens)

| Provider | Input | Output | Cached input | Context |
|---|---|---|---|---|

## FAQ

### What is the context window of Qwen3.5 9B Base?

Qwen3.5 9B Base has a context window of 65,536 tokens (66K) and can generate up to 65,536 tokens in a single response, according to models.dev.

### Is Qwen3.5 9B Base open source?

Qwen3.5 9B Base is an open-weight model. Check the license terms before commercial use.

### When was Qwen3.5 9B Base released?

Alibaba (Qwen) released Qwen3.5 9B Base on 26 Feb 2026, according to models.dev.

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Data licensed CC BY 4.0. Cite as: AI Model Directory, "Qwen3.5 9B Base", https://www.aimodel.directory/models/qwen3-5-9b-base