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AI model comparison

GPT-6 Luna vs Kimi K3.1 Pro

A side-by-side comparison of GPT-6 Luna from OpenAI and Kimi K3.1 Pro from Moonshot AI, using published pricing, context windows, supported inputs, and release dates.

GPT-6 Luna input
$0.1
Kimi K3.1 Pro input
$2
At a glance

Key differences

GPT-6 Luna is 95% cheaper on input tokens ($0.1 vs $2 per 1M).

GPT-6 Luna has the larger context window: 1.05M vs 1.05M tokens.

Kimi K3.1 Pro is the newer release (Oct 23, 2026, vs Sep 22, 2026).

Side by side

GPT-6 Luna vs Kimi K3.1 Pro specs

SpecGPT-6 LunaKimi K3.1 Pro
ProviderOpenAIMoonshot AI
ReleasedSep 22, 2026Oct 23, 2026
Context window1,050,000 tokens1,048,576 tokens
Input price / 1M tokens$0.1$2
Output price / 1M tokens$0.5$10
10K in + 1K out request$0.0015$0.03
Acceptsfile, image, textimage, text, video
Producestexttext
Tool callingYesYes
Structured outputsYesYes
ReasoningYesYes
Popularity48/10041/100

Highlighted values are better on that spec: lower price, larger context window, newer release, or higher popularity. Prices in USD per 1M tokens as listed on OpenRouter.

FAQ

GPT-6 Luna vs Kimi K3.1 Pro questions

Is GPT-6 Luna or Kimi K3.1 Pro cheaper?

GPT-6 Luna has the lower listed input price ($0.1 per million tokens). For a request with 10,000 input and 1,000 output tokens, GPT-6 Luna costs about $0.0015 and Kimi K3.1 Pro about $0.03.

Which has the larger context window?

GPT-6 Luna supports 1,050,000 tokens, the larger of the two.

Which model should I choose?

Pick the cheaper model for high-volume, simpler tasks, and test both on a sample of your real prompts before committing. Price and context size do not measure output quality on your specific workload.