GPT-6 Luna Pro vs Mercury 3

Price, context window & benchmark comparison

OpenAI

GPT-6 Luna Pro

OpenAI
$0.10 / $0.50
Input / Output · per 1M tokens
VS
Inception

Mercury 3

Inception
$0.10 / $0.35
Input / Output · per 1M tokens
Compare different models
OpenAI
Inception
Verdict: Mercury 3 is 19% cheaper than GPT-6 Luna Pro on a typical 3:1 input/output mix. GPT-6 Luna Pro has the larger context window (1.1M vs 1M).
GPT-6 Luna ProMercury 3
Input price / 1M$0.10$0.10
Output price / 1M$0.50$0.35
Blended price (3:1)$0.20$0.16
Cached input / 1M$0.01$0.01
Context window1.1M1M
Max output128K131K
Intelligence index——
Coding index——
Providers6—
Best provider uptime (30m)100.0%—
Vision inputYesNo
ReasoningYesYes
Tool callingYesYes
Released2026-09-222026-10-16
Retirement——

Cost calculator

FAQ

Which is cheaper, GPT-6 Luna Pro or Mercury 3?

Mercury 3 is 19% cheaper than GPT-6 Luna Pro on a typical 3:1 input/output mix.

GPT-6 Luna Pro vs Mercury 3: which has a bigger context window?

GPT-6 Luna Pro: 1,050,000 tokens. Mercury 3: 1,000,000 tokens.

How much would 1 million requests cost?

At 2,000 input + 500 output tokens per request: GPT-6 Luna Pro ≈ $450.00, Mercury 3 ≈ $375.00.

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