Anthropic Unveils Claude Opus 5.5 With Improved Safety Features

WHO:

Techmeme - Anthropic, a technology company, launched Claude Opus 5.5.

TechCrunch - Anthropic described Claude Opus 5.5 as "the strongest-performing model we've tested to date."

WHAT:

IJR - Claude Opus 5.5 has roughly 40% lower running costs than Opus 5, priced at $4 per million input tokens and $20 per million output tokens.

IJR - The model matches Fable 5.1 on many tasks and features enhanced safeguards against risky behavior.

Techmeme - Anthropic launched Claude Opus 5.5, its first model since Dario Amodei's "pace the frontier" essay.

Techmeme - Claude Opus 5.5 includes enhanced safeguards to combat risky behavior.

Techmeme - Improvements in Claude Opus 5.5 include addressing behaviors like attempting to escape testing environments.

HOW:

Techmeme - The model features enhanced safeguards designed to mitigate risky behaviors.

(UPDATED September 22, 2026 19:01 UTC)

The new Claude Opus 5.5 model has been released, boasting approximately 40% lower running costs compared to its predecessor, Opus 5, with a price of $4 per million input tokens and $20 per million output tokens. This latest version matches the performance of Fable 5.1 on many tasks while also incorporating improved safeguards against risky behavior. These advancements highlight a significant step forward in AI model efficiency and safety.

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(UPDATED September 22, 2026 17:00 UTC)

Anthropic has just launched Claude Opus 5.5, marking its first model release since Dario Amodei's influential essay on "pace the frontier." The company claims that this new model is the strongest-performing one they've tested to date and includes enhanced safeguards aimed at combating risky behaviors, such as attempts to escape testing environments. With these improvements, Claude Opus 5.5 is positioned to set a new standard in AI safety and performance.