GPT-5.6 Luna vs Grok 4.6
GPT-5.6 Luna (OpenAI) and Grok 4.6 (xAI) compared on benchmarks, pricing, context window, and use-case rankings.
- GPT-5.6 Luna leads on overall intelligence (ECI 156 vs 156).
- GPT-5.6 Luna is cheaper on input tokens — $0.20 vs $2.00 per 1M.
- GPT-5.6 Luna has a larger context window (1.1M vs 500K tokens).
- Grok 4.6 ranks higher for coding (91th vs 76th percentile).
| Attribute | GPT-5.6 Luna | Grok 4.6 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 156 | 156 |
| Coding | 76 | 91 |
| Math | 87 | 93 |
| Reasoning & Knowledge | 57 | 76 |
| Agentic & Tools | — | 89 |
| Specifications | ||
| Developer | OpenAI | xAI |
| Family | GPT | Grok |
| Released | Jul 9, 2026 | Aug 12, 2026 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 1.1M | 500K |
| Price — $/M input | $0.20 | $2.00 |
| Price — $/M output | $1.20 | $6.00 |
| Inputs | file, image, text | text, image, file |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 98% | 99% |
| ARC-AGI | 88% | 88% |
| ARC-AGI-2 | 60% | 67% |
| GPQA Diamond | 92% | 94% |
| Humanity's Last Exam | 40% | 43% |
| SciCode | 53% | 54% |
| SimpleBench | 47% | — |
| SimpleQA Verified | 42% | 54% |
| WebDev Arena | 1523 | 1631 |
| WeirdML | 61% | 67% |
| APEX | — | 41% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Is GPT-5.6 Luna better than Grok 4.6?
On Epoch AI's Capabilities Index, GPT-5.6 Luna scores higher (156) than Grok 4.6 (156). The right pick depends on your task — compare their coding, math, and reasoning scores in the table above.
Which is cheaper, GPT-5.6 Luna or Grok 4.6?
GPT-5.6 Luna is cheaper on input tokens at $0.20 per million, versus $2.00 (representative OpenRouter pricing).
Which has a larger context window, GPT-5.6 Luna or Grok 4.6?
GPT-5.6 Luna supports up to 1.1M tokens, compared with 500K for the other.
Which is better for coding, GPT-5.6 Luna or Grok 4.6?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Grok 4.6 ranks higher — 91th vs 76th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.