Claude Opus 4.8 sits at the top of Anthropic's widely-available lineup. In Anthropic's own words it's the model "for complex agentic coding and enterprise work" — the one you reach for when a task is long, multi-step, and expensive to get wrong. Below it is Sonnet 5 for balanced speed-and-intelligence; above it, in limited availability, is the Fable/Mythos tier.
The spec sheet is deliberately unglamorous and mostly shared with the rest of the current generation: a 1-million-token context window, up to 128K output tokens, a January 2026 knowledge cutoff, and adaptive thinking where the model itself decides how hard to think (tuned by an effort dial that defaults to high). What sets Opus apart isn't a headline number — it's that Anthropic positions it as its most capable model for autonomous, long-horizon agentic work.
Who it's for
Teams doing the hard stuff: large refactors, overnight coding runs, multi-tool agents, and enterprise workflows where capability matters more than the per-token bill. The 1M-token context is billed at standard rates, so whole-repo and long-document tasks don't carry a long-context surcharge. If you need lower latency and can absorb the premium, a fast-mode research preview roughly doubles the price for significantly faster output.
Who should skip it
Anyone cost-sensitive or latency-sensitive. At $5 / $25 per million tokens Opus 4.8 is about 2.5x the price of Sonnet 5, and Sonnet 5 is faster by default and now near-frontier on coding — for most production workloads it's the more economical call. Opus is also closed and hosted-only: there are no weights to download, run offline, or audit, so if ownership or on-prem is a hard requirement, this isn't the model.
This is a first look built from Anthropic's official documentation, not our own evaluation — so no score from us yet. On paper, Opus 4.8 is the capability ceiling of the general Claude lineup; whether you need that ceiling (and its price) over Sonnet 5 is the real decision.