GPT-5.6 Luna vs Grok 4.6
GPT-5.6 Luna and Grok 4.6 are closely matched at 45.3 and 47.1 on the LLM Stats Score. GPT-5.6 Luna is 6.7x cheaper per token.
OpenAI · xAI · Updated for 2026
Which is better?
GPT-5.6 Luna and Grok 4.6 are closely matched on the overall LLM Stats Score at 45.3 and 47.1.
The models split the 2 individual benchmarks reported for both models evenly.
On price, GPT-5.6 Luna is roughly 6.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.6 Luna also accepts a larger context window (1,050,000 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-5.6 Luna
- cost matters — it's about 6.7x cheaper per token
- you process long inputs — it offers a 1,050,000 token context window
Choose Grok 4.6
- your work emphasizes reasoning and agents — it leads those capability indexes
- you want the most recent training data — it shipped Aug 2026
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
45 reported for GPT-5.6 Luna · 11 for Grok 4.6
GPT-5.6 Luna outperforms in 1 benchmarks (DeepSWE 1.1), while Grok 4.6 is better at 1 benchmark (Terminal-Bench 4.0).
Both models are evenly matched across the benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5.6 Luna ($0.20/1M tokens) is 10.0x cheaper than Grok 4.6 ($2.00/1M tokens).
For output processing, GPT-5.6 Luna ($1.20/1M tokens) is 5.0x cheaper than Grok 4.6 ($6.00/1M tokens).
In conclusion, Grok 4.6 is more expensive than GPT-5.6 Luna.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.6 Luna accepts 1,050,000 input tokens compared to Grok 4.6's 500,000 tokens. Only GPT-5.6 Luna specifies output context (128,000 tokens).
Input capabilities
Documented input modalities across available providers
Both GPT-5.6 Luna and Grok 4.6 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5.6 Luna
Grok 4.6
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-5.6 Luna was released on 2026-07-09, while Grok 4.6 was released on 2026-08-12.
Grok 4.6 is 1 month newer than GPT-5.6 Luna.
Jul 9, 2026
2 months ago
Aug 12, 2026
4 weeks ago
1mo newerKnowledge Cutoff
When training data ends
GPT-5.6 Luna has a knowledge cutoff of 2026-02-16, while Grok 4.6 has a cutoff of 2026-02-01.
GPT-5.6 Luna has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to Grok 4.6 (2026-02-01).
Feb 2026
Feb 2026
Provider Availability
GPT-5.6 Luna is available from OpenAI. Grok 4.6 is available from xAI.
GPT-5.6 Luna
Grok 4.6
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5.6 Luna and Grok 4.6 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5.6 Luna vs Grok 4.6.