CURRENT UPGRADE CANDIDATE
Claude Opus 5.5
20% lower price · +8.8 estimated ECI vs announced successor
Claude Opus 4 is retired.
What replaces Claude Opus 4?
For a direct Anthropic API replacement for Claude Opus 4, compare Claude Opus 5.5 first. As of 2026-11-02, its verified Standard blended price is $8.00 per 1M tokens at a 75% input / 25% output mix. That is 20% below Claude Opus 4.8's current price, with a 8.8-point higher ECI estimate. ECI is an estimated general-capability measure; this is not a task-performance guarantee.
Historical ECI 142.4 · Current direct API price unavailable
REPLACEMENT DECISION
Replace Claude Opus 4 today.
Direct API prices at 75% input / 25% output. ECI is estimated general capability, not task success.
MINIMIZE COST · SAME PROVIDER
Claude Sonnet 5
Lower ECI estimate may mean a capability tradeoff.
ORIGINALLY ANNOUNCED BY ANTHROPIC
Claude Opus 4.8
Historical provider guidance, retained as a reference.
Current upgrade: at least 10% cheaper, 2 more ECI points and no less published context than the announced replacement. The low-cost option retains context and clears the retired model's ECI lower bound. ECI intervals can overlap; no choice guarantees task results or API compatibility.
Replacement questions
Which replacement did Anthropic announce for Claude Opus 4?
Anthropic announced Claude Opus 4.8. As of 2026-11-02, its verified Standard blended price is $10.00 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 Opus 4 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.