GPT-6 Luna vs Grok-4.1 Fast Non-Reasoning
Comparing GPT-6 Luna and Grok-4.1 Fast Non-Reasoning across benchmarks, pricing, and capabilities.
OpenAI · xAI · Updated for 2026
Which is better?
GPT-6 Luna and Grok-4.1 Fast Non-Reasoning trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, GPT-6 Luna is roughly 1.4x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-4.1 Fast Non-Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-6 Luna
- cost matters — it's about 1.4x cheaper per token
- you want the most recent training data — it shipped Sep 2026
Choose Grok-4.1 Fast Non-Reasoning
- you process long inputs — it offers a 2,000,000 token context window
At a glance
The differences that matter most.
Individual benchmarks
5 reported for GPT-6 Luna · 0 for Grok-4.1 Fast Non-Reasoning
GPT-6 Luna and Grok-4.1 Fast Non-Reasoningdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-6 Luna ($0.10/1M tokens) is 2.0x cheaper than Grok-4.1 Fast Non-Reasoning ($0.20/1M tokens).
For output processing, GPT-6 Luna ($0.50/1M tokens) costs the same as Grok-4.1 Fast Non-Reasoning ($0.50/1M tokens).
In conclusion, Grok-4.1 Fast Non-Reasoning is more expensive than GPT-6 Luna.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4.1 Fast Non-Reasoning accepts 2,000,000 input tokens compared to GPT-6 Luna's 1,050,000 tokens. GPT-6 Luna can generate longer responses up to 128,000 tokens, while Grok-4.1 Fast Non-Reasoning is limited to 30,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-6 Luna and Grok-4.1 Fast Non-Reasoning support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-6 Luna
Grok-4.1 Fast Non-Reasoning
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-6 Luna was released on 2026-09-22, while Grok-4.1 Fast Non-Reasoning was released on 2025-11-17.
GPT-6 Luna is 10 months newer than Grok-4.1 Fast Non-Reasoning.
Sep 22, 2026
0 days ago
10mo newerNov 17, 2025
10 months ago
Knowledge Cutoff
When training data ends
GPT-6 Luna has a documented knowledge cutoff of 2026-05-18, while Grok-4.1 Fast Non-Reasoning's cutoff date is not specified.
We can confirm GPT-6 Luna's training data extends to 2026-05-18, but cannot make a direct comparison without Grok-4.1 Fast Non-Reasoning's cutoff date.
May 2026
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Provider Availability
GPT-6 Luna is available from OpenAI. Grok-4.1 Fast Non-Reasoning is available from xAI.
GPT-6 Luna
Grok-4.1 Fast Non-Reasoning
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-6 Luna and Grok-4.1 Fast Non-Reasoning side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-6 Luna vs Grok-4.1 Fast Non-Reasoning.