Everything Claude Opus 5.5 Actually Ships With
Anthropic released Claude Opus 5.5 on September 22, 2026. It's the first model in the new Claude 5.5 family, and according to Anthropic's own announcement, it performs at roughly the level of Claude Fable 5.1 on most work while costing 40% less to run than Opus 5. This article pulls together every verifiable number and detail from Anthropic's announcement, the platform documentation, the system card, and independent coverage, so you have one place to check the facts.
- ▪Anthropic released Claude Opus 5.5 on September 22, 2026.
- ▪It's the first model in the new Claude 5.5 family, and according to Anthropic's own announcement, it performs at roughly the level of Claude Fable 5.1 on most work while costing 40% less to run than Opus 5.
- ▪This article pulls together every verifiable number and detail from Anthropic's announcement, the platform documentation, the system card, and independent coverage, so you have one place to check the facts.
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| Original publisher | KDnuggets |
| Canonical URL | https://www.kdnuggets.com/everything-claude-opus-5-5-actually-ships-with |
| Publication time | Wed, 23 Sep 2026 15:00:47 +0000 |
| Retrieval time | 2026-09-23T15:09:30.654Z |
| Last seen | 2026-09-23T15:09:30.654Z |
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Opening excerpt (first ~120 words) tap to expand
Anthropic released Claude Opus 5.5 on September 22, 2026. It's the first model in the new Claude 5.5 family, and according to Anthropic's own announcement, it performs at roughly the level of Claude Fable 5.1 on most work while costing 40% less to run than Opus 5. This article pulls together every verifiable number and detail from Anthropic's announcement, the platform documentation, the system card, and independent coverage, so you have one place to check the facts. Opus 5.5 arrived two months after Opus 5, which launched July 24, 2026, per TechCrunch's coverage. Anthropic describes it as "the strongest-performing model we've tested to date" on its internal alignment testing. Sonnet 5.5 and Haiku 5.5 are both confirmed to launch soon after, per the same announcement.
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