GPT-5.6 Luna vs GPT-6.1 Terra

Price, context window & benchmark comparison

OpenAI

GPT-5.6 Luna

OpenAI
$0.20 / $1.20
Input / Output · per 1M tokens
VS
OpenAI

GPT-6.1 Terra

OpenAI
$1.00 / $5.00
Input / Output · per 1M tokens
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OpenAI
OpenAI
Verdict: GPT-5.6 Luna is 4.4× cheaper than GPT-6.1 Terra on a typical 3:1 input/output mix. GPT-6.1 Terra scores higher on the Artificial Analysis Intelligence Index (51.3 vs 23.8).
GPT-5.6 LunaGPT-6.1 Terra
Input price / 1M$0.20$1.00
Output price / 1M$1.20$5.00
Blended price (3:1)$0.45$2.00
Cached input / 1M$0.02$0.05
Context window1.1M1.1M
Max output128K128K
Intelligence index23.851.3
Coding index71.4—
Providers77
Best provider uptime (30m)100.0%100.0%
Vision inputYesYes
ReasoningYesYes
Tool callingYesYes
Released2026-07-092026-10-26
Retirement——

Cost calculator

FAQ

Which is cheaper, GPT-5.6 Luna or GPT-6.1 Terra?

GPT-5.6 Luna is 4.4× cheaper than GPT-6.1 Terra on a typical 3:1 input/output mix.

GPT-5.6 Luna vs GPT-6.1 Terra: which has a bigger context window?

GPT-5.6 Luna: 1,050,000 tokens. GPT-6.1 Terra: 1,050,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: GPT-5.6 Luna ≈ $1,000, GPT-6.1 Terra ≈ $4,500.

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