Model releases & benchmarks
Introducing Claude Opus 5.5
Anthropic positions Claude Opus 5.5 as a capability-and-efficiency upgrade: performance it says is comparable to Fable 5.1 on most work, with typical-workload costs 40% below Opus 5.
Why it matters: For teams choosing a model for long-running coding or research workflows, lower per-token prices and fewer tokens per task could reduce costs. But the source’s benchmark caveat and stated limits of alignment testing mean task-specific evaluation and safeguards remain important.