Anthropic · Model release
Claude Opus 5: July 2026 launch, now superseded by Opus 5.5
At its July 2026 launch, Claude Opus 5 targeted complex agentic coding and long-horizon work with a 1-million-token context. Opus 5.5 launched on 2026-09-22 at lower $4/$20 rates; Anthropic now lists Opus 5 as Active (legacy), so compare Opus 5.5 first for new work.
What changed
- Anthropic positions Opus 5 as a major reasoning and long-horizon upgrade.
- Thinking is enabled by default and effort controls change how cost and latency behave.
- The model is available through the Anthropic API and cloud model catalogues.
Best fit
- Difficult debugging
- Long-context analysis
- Agentic engineering
What to be careful about
- Output pricing and long generations can dominate the bill.
- A frontier model is wasteful for routine extraction and simple classification.
- Superseded: Opus 5.5 is cheaper ($4/$20 vs $5/$25) and scores higher on the AA Intelligence Index v4.3.2 (58 vs 51, publisher-rounded at max effort) — start new work there.
Dataset snapshot: Claude Opus 5 is also represented in the checked comparison dataset. Prices and benchmark figures carry their own field dates.