PROVIDER MIGRATION PATH
Claude Sonnet 5.5
Anthropic's announced successor.
Claude 3.5 Sonnet (June 2024) is retired.
What replaces Claude 3.5 Sonnet (June 2024)?
For a direct Anthropic API replacement for Claude 3.5 Sonnet (June 2024), compare Claude Sonnet 5.5 first. As of 2026-11-02, its verified Standard blended price is $4.00 per 1M tokens at a 75% input / 25% output mix. ECI is an estimated general-capability measure; this is not a task-performance guarantee.
Historical ECI 130.0 · Current direct API price unavailable
REPLACEMENT DECISION
Provider migration path.
Direct API prices at 75% input / 25% output. ECI is estimated general capability, not task success.
ECI intervals can overlap; no choice guarantees task results or API compatibility.
Replacement questions
Which replacement did Anthropic announce for Claude 3.5 Sonnet (June 2024)?
Anthropic announced Claude Sonnet 5.5. As of 2026-11-02, its verified Standard blended price is $4.00 per 1M tokens at a 75% input / 25% output mix. This historical provider advice can differ from today's price-and-ECI screening choice. Provider notice.
Is the replacement for Claude 3.5 Sonnet (June 2024) API compatible?
API compatibility has not been verified. Check the provider's migration guidance and test your integration before switching.
Prices verified 2026-11-02; ECI snapshot 2026-11-01. Retirement applies to the Anthropic direct API; seller routes need separate evidence. Retirement notice · ECI data · Browse current models.