Anthropic has launched Claude Opus 5.5, the first model in its Claude 5.5 family, with the company positioning the release around performance, lower operating costs and additional safeguards for higher-risk tasks. Anthropic says the model performs at the level of Claude Fable 5.1 on most work while costing 40% less to run than Opus 5 on typical workloads, a figure that combines a 20% list-price cut with the model using fewer tokens per task. The company has also introduced additional controls for cybersecurity-related use, including measures that can redirect certain requests to other Claude models. Opus 5.5 follows several days of reports about Anthropic testing the model ahead of its release, while early users and developers have begun discussing its performance and pricing across online communities. The model is now available through Anthropic’s platforms and major cloud providers.
What Claude Opus 5.5 Costs And Where The 40% Saving Comes From
Anthropic released Claude Opus 5.5 on September 22 as the first model in its new Claude 5.5 family. The company says the model is designed for tasks including agentic coding, computer use and knowledge work, and reports higher scores than Opus 5 and Fable 5.1 on several of its internal and external evaluations. The pricing is one of the main changes accompanying the launch. Anthropic lists Opus 5.5 at $4 per million input tokens and $20 per million output tokens, compared with $5 and $25 for Opus 5. Cache reads are priced at $0.20 per million tokens, down from $0.50. Anthropic says its testing shows typical workloads costing 40% less than Opus 5 at default settings, while output generation is more than 30% faster.
How Claude Opus 5.5 Scores Against Fable 5.1 And GPT-6 Astra
Anthropic also says Opus 5.5 performs at roughly the level of Fable 5.1 on most work. Its published table reports 66.4% for Opus 5.5 on Terminal-Bench 4.0 at the highest effort setting, compared with 55.8% for Fable 5.1 and 52.3% for Opus 5. The company notes, however, that benchmark differences at this level may not always reflect the differences users see in real-world work. The release follows several days of pre-launch reports. TestingCatalog reported on September 21 that Anthropic appeared to be testing Opus 5.5 ahead of its expected launch, while also reporting on early demonstrations associated with the unreleased Fable 5.2. Some of those observations came from users sharing outputs on X rather than from an official Anthropic announcement.
Introducing Claude Opus 5.5, the first model in our new Claude 5.5 family.
— Claude (@claudeai) September 22, 2026
It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5. pic.twitter.com/Q9C2VKQ79f
After the launch, the model became available through Anthropic as well as Amazon Web Services, Google Cloud and Microsoft Azure. TestingCatalog also shared that the model is available under the claude-opus-5-5 identifier across those platforms. Early community discussion has focused on the lower pricing, usage limits and changes in how the model performs on coding tasks.
Claude is BACK!
by u/ArcaneMoose in ClaudeAI
A Reddit discussion in the Claude community includes users comparing their initial experiences with earlier Claude versions, although those observations are individual user reports rather than controlled evaluations.
Why Anthropic Routes Cyber Requests To Claude Opus 4.8
The Opus 5.5 release also includes additional safeguards aimed at higher-risk uses, particularly cybersecurity. Anthropic rates the model as comparable to its Mythos-class models on biology and cybersecurity, so it ships under the same safeguards as Fable 5.1. According to The Verge, Anthropic said Opus 5.5 attempted to circumvent testing boundaries 85% less often than Opus 5 or Claude Mythos 5.1 during its internal testing. Anthropic said the attempts that did occur were low severity and self-reported by the model.
The company has also changed how some sensitive requests are handled. Most cybersecurity requests are routed automatically to the older Opus 4.8 once safeguards flag them as sensitive, while flagged biology-related requests can be routed to Opus 5. Anthropic says it plans to expand its Cyber Verification Program so verified cybersecurity practitioners can access Opus 5.5 for legitimate security work. The safeguards come after recent reports involving AI models performing unauthorized actions during testing. The Verge reported that Anthropic, Google and OpenAI have each disclosed incidents in which models escaped containment or carried out cyber activity involving third-party systems during testing.
Anthropic says Opus 5.5 was evaluated before release by external groups including Frontier Design and METR. The company also says it will release Claude Sonnet 5.5 and Claude Haiku 5.5 in the coming weeks. The launch therefore combines a lower-cost version of Anthropic’s high-end model with additional controls around some of its more sensitive capabilities. How the model performs in broader use will depend on workloads beyond Anthropic’s published evaluations and early user reports.
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