Anthropic Drops Claude Opus 5.5 — New AI Model Matches Claude Fable 5.1 While Costing 40% Less

• Opus 5.5 is the first model in Anthropic’s Claude 5.5 family and performs at the level of Claude Fable 5.1 on most work.
• The model generates output more than 30% faster than Opus 5, while its Fast mode can deliver speeds of up to 2.5x.
• Claude Sonnet 5.5 and Claude Haiku 5.5 are due in the coming weeks, with similar improvements in performance, efficiency and safety.

Anthropic said it has launched Claude Opus 5.5, the first model in its new Claude 5.5 family, with the company highlighting gains in performance, coding, speed and safety. Anthropic said in a blog post that the model performs at the level of Claude Fable 5.1 on most work while costing 40% less to run than Opus 5, with early testers reporting major improvements on complex tasks.

Lower Costs, Faster Output

The biggest efficiency gain comes from the model’s lower compute requirements. Anthropic said its tests show that Opus 5.5 costs 40% less than Opus 5 on typical workloads at default settings. Input and output tokens are priced at $4 and $20 per million, respectively, while cache reads cost $0.20 per million tokens.

Opus 5.5 also generates output more than 30% faster than Opus 5. Anthropic is additionally offering a Fast mode through Claude Code and the Claude Platform, with speeds up to 2.5 times faster.

AI Safety Debate

The launch comes as Anthropic and the broader AI industry face growing scrutiny over the risks associated with increasingly capable models. Earlier this month, Anthropic CEO Dario Amodei called on the global AI community to slow the pace of releasing new capabilities to address safety concerns.

Ahead of its release, independent AI safety research groups Frontier Design and METR tested Opus 5.5, according to Anthropic. The company also said the model includes safeguards previously used for its most capable systems.

Opus 5.5 is available through Amazon.com’s (AMZN) Amazon Web Services, Alphabet’s (GOOGL) Google Cloud and Microsoft’s (MSFT) Microsoft Azure.

Built For Complex Coding Jobs

Anthropic said Opus 5.5 is particularly suited to long and complex coding tasks, including codebase-wide migrations and audits. One early tester used the model to audit and fix a 200,000-line codebase in under three hours, compared with more than 20 hours using Opus 5, which also used 2.5 times as many tokens.

More Claude 5.5 Models Coming

Anthropic said Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks, with many of the same improvements in performance, efficiency and safety.

Opus 5.5 also brings changes to how the model communicates. Early testers described its writing as clearer and easier to follow, while Anthropic said the model puts the most important information upfront and is easier to work with during longer sessions.

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