Anthropic

Claude Opus 5.5

Generally availableProprietary1M contextReasoning

Summary

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.

Claude model for long-running agentic coding and knowledge work

Last verified 4 Oct 2026. Every figure on this page links to its source.

Specifications

DeveloperAnthropic
Release date22 Sept 2026 [models.dev]
StatusGenerally available [models.dev]
WeightsProprietary (API only) [models.dev]
Context window1M (1,000,000 tokens) [models.dev]
Max output128K tokens [models.dev]
Knowledge cutoffJun 2026 [models.dev]
InputText, images and PDFs [models.dev]
OutputText [models.dev]
Reasoning modeYes [models.dev]
Tool callingYes [models.dev]
Structured outputYes [models.dev]

Claude Opus 5.5 API pricing by provider

USD per million tokens. Sorted by input price.

ProviderInputOutputCached inputContextSource
Claude API
claude-opus-5-5
$4$20$0.201Mmodels.dev, 4 Oct 2026
Azure AI Foundry
claude-opus-5-5
$4$20$0.201Mmodels.dev, 4 Oct 2026
Amazon Bedrock
anthropic.claude-opus-5-5
$4$20$0.201Mmodels.dev, 4 Oct 2026
Vertex AI (Claude)
claude-opus-5-5@default
$4$20$0.201Mmodels.dev, 4 Oct 2026
Amazon Bedrock
global.anthropic.claude-opus-5-5
$4$20$0.201Mmodels.dev, 4 Oct 2026
Google Vertex AI
claude-opus-5-5@default
$4$20$0.201Mmodels.dev, 4 Oct 2026
Vercel AI Gateway
anthropic/claude-opus-5.5
$4$20$0.201Mmodels.dev, 4 Oct 2026
OpenRouter
anthropic/claude-opus-5.5
$4$20$0.201MOpenRouter, 4 Oct 2026
Amazon Bedrock
eu.anthropic.claude-opus-5-5
$4.40$22$0.221Mmodels.dev, 4 Oct 2026
Amazon Bedrock
au.anthropic.claude-opus-5-5
$4.40$22$0.221Mmodels.dev, 4 Oct 2026
Amazon Bedrock
us.anthropic.claude-opus-5-5
$4.40$22$0.221Mmodels.dev, 4 Oct 2026
Amazon Bedrock
jp.anthropic.claude-opus-5-5
$4.40$22$0.221Mmodels.dev, 4 Oct 2026
Vercel AI Gateway
anthropic/claude-opus-5.5-fast
$8$40$0.401Mmodels.dev, 4 Oct 2026

Frequently asked questions

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.

Change history

No changes detected since we started tracking this model. We re-check every source daily.

Sources