WhichAI / Models / Claude Sonnet 5.5

Claude Sonnet 5.5

· verified October 3, 2026

public paid api reasoning vision long-context

Provider

Statuspublic

AA Intelligence Index56 (official, read October 3, 2026)

Released2026-09-28

Context window1M

ModalitiesText + image + files

API price $/1M (in / out)$2 / $10 (OpenRouter)

Speedn/a

AccessAPI $2/$10 per 1M tokens on OpenRouter · listed September 28, 2026

In one line

Claude Sonnet 5.5 by Anthropic, measured by Artificial Analysis at 56 on the Intelligence Index. Added to WhichAI automatically from live data on October 3, 2026: no editorial review yet, so judge it by the numbers, not by a verdict. OpenRouter's description: “Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.”

Alternatives worth a look

Claude Opus 5.5 (Anthropic) · AA 57.6API $4/$20 per 1M tokens on OpenRouter · listed September 22, 2026
Claude Fable 5.1 (Anthropic) · AA 53.4Released September 1, 2026 · Claude Pro and Max · API $10/$50 per 1M tokens ($0.25 cached)
GPT-6 Astra (OpenAI) · AA 52.7Released September 4, 2026 · API $10/$50 per 1M tokens ($1 cached) · ChatGPT Plus and Pro · batch tier at $5/$25

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Artificial Analysis Intelligence Index, official scale (the number published on artificialanalysis.ai), relayed by OpenRouter and refreshed automatically: last read October 3, 2026. 97 models carry a current official measurement. A value marked ~ is converted from an earlier snapshot because no current measurement is published; an unmeasured model is never ranked. Context, price, modality and listing dates come from the public OpenRouter model list (refreshed automatically on the live site; static copy retrieved October 3, 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).