# Claude Opus 5.5

> Claude Opus 5.5 is a proprietary language model from Anthropic, released on 22 Sept 2026. It accepts text, images and PDFs and generates text, with a 1M-token context window and up to 128K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $4 per million input tokens and $20 per million output tokens (Claude API), across 7 providers we track.

Source page: https://www.aimodel.directory/models/claude-opus-5-5
Last verified: 4 Oct 2026

## Specifications

- **Developer:** Anthropic
- **Release date:** 22 Sept 2026 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Status:** Generally available (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Weights:** Proprietary (API only) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Context window:** 1M (1,000,000 tokens) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Max output:** 128K tokens (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Knowledge cutoff:** Jun 2026 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Input:** Text, images and PDFs (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Output:** Text (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Reasoning mode:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Tool calling:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)
- **Structured output:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-opus-5-5.toml)

## API pricing (USD per 1M tokens)

| Provider | Input | Output | Cached input | Context |
|---|---|---|---|---|
| Claude API | $4 | $20 | $0.20 | 1M |
| Azure AI Foundry | $4 | $20 | $0.20 | 1M |
| Amazon Bedrock | $4 | $20 | $0.20 | 1M |
| Vertex AI (Claude) | $4 | $20 | $0.20 | 1M |
| Amazon Bedrock | $4 | $20 | $0.20 | 1M |
| Google Vertex AI | $4 | $20 | $0.20 | 1M |
| Vercel AI Gateway | $4 | $20 | $0.20 | 1M |
| OpenRouter | $4 | $20 | $0.20 | 1M |
| Amazon Bedrock | $4.40 | $22 | $0.22 | 1M |
| Amazon Bedrock | $4.40 | $22 | $0.22 | 1M |
| Amazon Bedrock | $4.40 | $22 | $0.22 | 1M |
| Amazon Bedrock | $4.40 | $22 | $0.22 | 1M |
| Vercel AI Gateway | $8 | $40 | $0.40 | 1M |

## FAQ

### What is the context window of Claude Opus 5.5?

Claude Opus 5.5 has a context window of 1,000,000 tokens (1M) and can generate up to 128,000 tokens in a single response, according to models.dev.

### How much does the Claude Opus 5.5 API cost?

Through Claude API, Claude Opus 5.5 costs $4 per million input tokens and $20 per million output tokens. Prices last verified 4 Oct 2026.

### Is Claude Opus 5.5 open source?

No. Claude Opus 5.5 is a proprietary model; Anthropic has not released its weights. It is available through APIs including Claude API, Azure AI Foundry, Amazon Bedrock, Vertex AI (Claude).

### When was Claude Opus 5.5 released?

Anthropic released Claude Opus 5.5 on 22 Sept 2026, according to models.dev.

### Which providers offer Claude Opus 5.5?

We track Claude Opus 5.5 on 7 providers: Claude API, Azure AI Foundry, Amazon Bedrock, Vertex AI (Claude), Google Vertex AI, Vercel AI Gateway, OpenRouter.

---
Data licensed CC BY 4.0. Cite as: AI Model Directory, "Claude Opus 5.5", https://www.aimodel.directory/models/claude-opus-5-5