# grok-4-1-fast-reasoning

> grok-4-1-fast-reasoning is a proprietary language model from xAI, released on 20 Nov 2025. It accepts text and images and generates text, with a 2M-token context window and up to 30K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $0.20 per million input tokens and $0.50 per million output tokens (Azure AI Foundry), across 2 providers we track.

Source page: https://www.aimodel.directory/models/grok-4-1-fast-reasoning
Last verified: 4 Oct 2026

## Specifications

- **Developer:** xAI
- **Release date:** 20 Nov 2025 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Status:** Generally available (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Weights:** Proprietary (API only) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Context window:** 2M (2,000,000 tokens) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Max output:** 30K tokens (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Knowledge cutoff:** Jun 2025 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Input:** Text and images (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Output:** Text (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Reasoning mode:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)
- **Tool calling:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/302ai/models/grok-4-1-fast-reasoning.toml)

## API pricing (USD per 1M tokens)

| Provider | Input | Output | Cached input | Context |
|---|---|---|---|---|
| Azure AI Foundry | $0.20 | $0.50 | $0.05 | 128K |
| Vercel AI Gateway | $0.20 | $0.50 | $0.05 | 1M |

## FAQ

### What is the context window of grok-4-1-fast-reasoning?

grok-4-1-fast-reasoning has a context window of 2,000,000 tokens (2M) and can generate up to 30,000 tokens in a single response, according to models.dev.

### How much does the grok-4-1-fast-reasoning API cost?

grok-4-1-fast-reasoning is listed from $0.20 per million input tokens and $0.50 per million output tokens (Azure AI Foundry). Prices last verified 4 Oct 2026.

### Is grok-4-1-fast-reasoning open source?

No. grok-4-1-fast-reasoning is a proprietary model; xAI has not released its weights. It is available through APIs including Azure AI Foundry, Vercel AI Gateway.

### When was grok-4-1-fast-reasoning released?

xAI released grok-4-1-fast-reasoning on 20 Nov 2025, according to models.dev.

### Which providers offer grok-4-1-fast-reasoning?

We track grok-4-1-fast-reasoning on 2 providers: Azure AI Foundry, Vercel AI Gateway.

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Data licensed CC BY 4.0. Cite as: AI Model Directory, "grok-4-1-fast-reasoning", https://www.aimodel.directory/models/grok-4-1-fast-reasoning