Gemini 3.1 Pro Preview Custom Tools vs GPT-6 Luna Pro

Price, context window & benchmark comparison

Gemini 3.1 Pro Preview Custom Tools

Google

$2.00 / $12.00

Input / Output · per 1M tokens

GPT-6 Luna Pro

OpenAI

$0.10 / $0.50

Input / Output · per 1M tokens

Compare different models

Verdict: GPT-6 Luna Pro is 22.5× cheaper than Gemini 3.1 Pro Preview Custom Tools on a typical 3:1 input/output mix. GPT-6 Luna Pro has the larger context window (1.1M vs 1M).

	Gemini 3.1 Pro Preview Custom Tools	GPT-6 Luna Pro
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 window	1M	1.1M
Max output	66K	128K
Intelligence index	—	—
Coding index	—	—
Providers	—	6
Best provider uptime (30m)	—	100.0%
Vision input	Yes	Yes
Reasoning	Yes	Yes
Tool calling	Yes	Yes
Released	2026-02-25	2026-09-22
Retirement	—	—

Cost calculator

Input tokens / requestOutput tokens / requestRequests / day

FAQ

Which is cheaper, Gemini 3.1 Pro Preview Custom Tools or GPT-6 Luna Pro?

GPT-6 Luna Pro is 22.5× cheaper than Gemini 3.1 Pro Preview Custom Tools on a typical 3:1 input/output mix.

Gemini 3.1 Pro Preview Custom Tools vs GPT-6 Luna Pro: which has a bigger context window?

Gemini 3.1 Pro Preview Custom Tools: 1,048,576 tokens. GPT-6 Luna Pro: 1,050,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: Gemini 3.1 Pro Preview Custom Tools ≈ $10,000, GPT-6 Luna Pro ≈ $450.00.

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