Claude Opus 5

Mon, 01 Jan 0001 00:00:00 +0000

Claude Opus 5 is the Opus-tier model of Anthropic’s fifth Claude generation, released 24 July 2026 with the identifier claude-opus-5. Anthropic positions it for “complex agentic coding and enterprise work” and recommends it as the default starting point for most workloads — below the Fable tier in capability, above Sonnet in both capability and price.

Nothing is published about how it is built. No parameter count, no layer count, no hidden dimension, no attention scheme, no training compute, no indication of whether it is a mixture of experts. Anthropic’s transparency documentation lists those categories explicitly as not disclosed. What can be said about this model is what it does, what it costs to use, and what constraints it ships under — which is what this page covers.

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Claude Opus 5