GPT-5.6 Terra vs GPT-6 Luna

Price, context window & benchmark comparison

OpenAI

GPT-5.6 Terra

OpenAI
$2.00 / $12.00
Input / Output · per 1M tokens
VS
OpenAI

GPT-6 Luna

OpenAI
$0.10 / $0.50
Input / Output · per 1M tokens
Compare different models
OpenAI
OpenAI
Verdict: GPT-6 Luna is 22.5× cheaper than GPT-5.6 Terra on a typical 3:1 input/output mix. GPT-5.6 Terra scores higher on the Artificial Analysis Intelligence Index (32.3 vs 27.9).
GPT-5.6 TerraGPT-6 Luna
Input price / 1M$2.00$0.10
Output price / 1M$12.00$0.50
Blended price (3:1)$4.50$0.20
Cached input / 1M$0.20$0.01
Context window1.1M1.1M
Max output128K128K
Intelligence index32.327.9
Coding index76.7—
Providers—8
Best provider uptime (30m)—100.0%
Vision inputYesYes
ReasoningYesYes
Tool callingYesYes
Released2026-07-092026-09-22
Retirement——

Cost calculator

FAQ

Which is cheaper, GPT-5.6 Terra or GPT-6 Luna?

GPT-6 Luna is 22.5× cheaper than GPT-5.6 Terra on a typical 3:1 input/output mix.

GPT-5.6 Terra vs GPT-6 Luna: which has a bigger context window?

GPT-5.6 Terra: 1,050,000 tokens. GPT-6 Luna: 1,050,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: GPT-5.6 Terra ≈ $10,000, GPT-6 Luna ≈ $450.00.

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