RETIRED DIRECT API · 2025-10-28

Claude 3.5 Sonnet (October 2024) is retired.

Claude Sonnet 5.5 is its announced replacement.

REPLACEMENT DECISION

Choose what matters now.

Current direct API prices, per 1M tokens at 75% input / 25% output. Higher ECI means higher estimated general capability.

ModelBlended priceECI estimateContext

RETIREDClaude 3.5 Sonnet (October 2024)Unavailable133.4128.5–137.7Unverified

ORIGINALLY ANNOUNCED REPLACEMENTClaude Sonnet 5.5$4.00per 1M tokens166.7163.6–171.31,000,000

The announced replacement is historical provider guidance, not an evergreen recommendation. Current upgrades require at least 10% lower price, 2 more ECI points and no less published context. ECI ranges may overlap; neither ECI nor context proves task success or API compatibility.

Prices verified 2026-11-02; current ECI snapshot 2026-11-01. The retired model has no verified current price or context here. Retirement applies to the Anthropic direct API; seller routes need separate evidence. Retirement notice · ECI data · Browse current models.