WhichAI / Models / Claude Opus 4.5

Claude Opus 4.5

Anthropic · verified September 8, 2026

legacy paid api coding
ProviderAnthropic
Statuslegacy
AA Intelligence Index40.8 (September 8, 2026 snapshot)
Releasedn/a
Context windown/a
Modalitiesn/a
API price $/1M (in / out)n/a
Speedn/a
AccessAPI (legacy)

In one line

The late-2025 flagship that made agentic coding mainstream; now two generations back.

Coding72
Reasoning70
Writing70
Agents & tools68

Category scores (0-100) are WhichAI blended ratings: public category leaderboards plus editorial judgment. Guidance, not official measurements.

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Artificial Analysis Intelligence Index, 2026 rebased scale (top models ~ 55-66). Snapshot: September 4, 2026 (BenchLM mirror), retrieved September 8, 2026. Specs and prices come from the OpenRouter public model list on the same date. Models nobody has measured carry no index score at all and never enter a ranking: where an estimate exists it is shown separately and labelled unmeasured. Context, price, modality and release dates come from the public OpenRouter model list (retrieved September 8, 2026) and vendor pages. Missing values are not published or not yet verified - shown as -. Sources are linked inside the app (Model guide and About > Methodology).