GPT 5.6 Luna
OpenAI · text, image → text
GPT-5.6 Luna is designed for cost-sensitive, high-volume workloads. It roughly corresponds to the nano model tier used in earlier GPT-5 families.
Input$1 /M
Output$6 /M
Cache read$0.1 /M
← ModelsGPT 5.6 Luna
Grok 4.1 Fast (reasoning)
GPT 5.6 Luna vs Grok 4.1 Fast (reasoning)
Compare GPT 5.6 Luna from OpenAI and Grok 4.1 Fast (reasoning) from Grok on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the AIHubMix API.
GPT 5.6 LunaGrok 4.1 Fast (reasoning)+ Add model · 2/4
Grok 4.1 Fast (reasoning)
Grok · text, image → text
Grok 4.1 is a new conversational model with significant improvements in real-world usability, delivering exceptional performance in creative, emotional, and collaborative interactions. It is more perceptive to nuanced user intent, more engaging to converse with, and more coherent in personality, while fully preserving its core intelligence and reliability. Built on large-scale reinforcement learning infrastructure, the model is optimized for style, personality, helpfulness, and alignment, and leverages frontier agentic reasoning models as reward evaluators to autonomously assess and iterate on responses at scale, significantly enhancing overall interaction quality.
Input$0.2 /M
Output$0.5 /M
Cache read$0.05 /M
Pricing & Specifications
Prices are per million tokens. Time to First Token and throughput are rolling averages measured on AIHubMix.
GPT 5.6 Luna
Grok 4.1 Fast (reasoning)
Input /M
$1
$0.2
Output /M
$6
$0.5
Cache read /M
$0.1
$0.05
Context length
1,050,000
1,000,000
Max output
128,000
2,000,000
Time to First Token
2.2 s
-
Throughput
88.4 tok/s
-
Modalities
textimage
textimage
Supported Parameters
toolsthinkingstructured outputs
function callingstructured outputsthinking
API Formats
chat_completions · responses
Released
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-
Promotional prices show the discounted rate; see each model page for promotion windows.
Activity Past 30 Days
Daily traffic served through AIHubMix — how demand for each model is trending.
gpt-5.6-lunagrok-4-1-fast-reasoning
Tokens / day
-
Requests / day
-
Performance Past 3 Days
Measured on real AIHubMix traffic, hourly buckets. Gaps mean no traffic in that hour.
gpt-5.6-lunagrok-4-1-fast-reasoning
Throughput (tok/s)
-
TTFT (s)
-
Uptime (%)
-
Cost calculator
Estimate your monthly bill for the same workload on each model.
Grok 4.1 Fast (reasoning)
$19.50 /mo
GPT 5.6 Luna
$150 /mo
Monthly = daily × 30. Discounted rates applied where a promotion is active.
FAQ
Which is cheaper: GPT 5.6 Luna, Grok 4.1 Fast (reasoning)?
Grok 4.1 Fast (reasoning): $0.5/M output tokens; GPT 5.6 Luna: $6/M. Use the cost calculator above to estimate your own workload.
How large is each context window?
GPT 5.6 Luna accepts 1,050,000 and Grok 4.1 Fast (reasoning) accepts 1,000,000 input tokens. Maximum output per request is 128,000 tokens on GPT 5.6 Luna and 2,000,000 tokens on Grok 4.1 Fast (reasoning).
What inputs and capabilities does each model support?
GPT 5.6 Luna accepts text and image input and supports tool calling, thinking and structured outputs; Grok 4.1 Fast (reasoning) accepts text and image input and supports function calling, structured outputs and thinking.
Can I call GPT 5.6 Luna and Grok 4.1 Fast (reasoning) with the same API key?
Yes. AIHubMix serves every model on this page behind one OpenAI-compatible endpoint, so switching between them is a one-line change to the model field — no second account, key or SDK.
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