CURRENT UPGRADE CANDIDATE
gpt-6.1-sol
11% lower price · +7.7 estimated ECI vs announced successor
GPT-3.5 Turbo (January 2024) is retired.
What replaces GPT-3.5 Turbo (January 2024)?
For a direct OpenAI API replacement for GPT-3.5 Turbo (January 2024), compare gpt-6.1-sol first. As of 2026-11-02, its verified Standard blended price is $4.00 per 1M tokens at a 75% input / 25% output mix. That is 11% below gpt-5.6-terra's current price, with a 7.7-point higher ECI estimate. ECI is an estimated general-capability measure; this is not a task-performance guarantee.
Historical ECI 115.6 · Current direct API price unavailable
REPLACEMENT DECISION
Replace GPT-3.5 Turbo (January 2024) today.
Direct API prices at 75% input / 25% output. ECI is estimated general capability, not task success.
MINIMIZE COST · SAME PROVIDER
gpt-6-luna
Lower ECI estimate may mean a capability tradeoff.
ORIGINALLY ANNOUNCED BY OPENAI
gpt-5.6-terra
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 OpenAI announce for GPT-3.5 Turbo (January 2024)?
OpenAI announced gpt-5.6-terra. As of 2026-11-02, its verified Standard blended price is $4.50 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 GPT-3.5 Turbo (January 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 OpenAI direct API; seller routes need separate evidence. Retirement notice · ECI data · Browse current models.