GPT-5.6 Luna (Medium) vs Grok 4.3 (High)
Which is better for the money: GPT-5.6 Luna (Medium) by OpenAI or Grok 4.3 (High) by SpaceXAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-25.
Clear winner
Verdict
Pick GPT-5.6 Luna (Medium)
Grok 4.3 (High) vs GPT-5.6 Luna (Medium): 0.4% less intelligence, 719.6% more cost to run the AA benchmark, and 372.5% slower end-to-end.
| Metric | GPT-5.6 Luna (Medium) | Grok 4.3 (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 25.0 | 24.9 | −0.4% Grok 4.3 (High) is 0.4% less intelligent |
| Total AA cost (lower is better) | $44.32 | $363.24 | +719.6% Grok 4.3 (High) is 8.2× more expensive |
| End-to-end time (lower is better) | 6.11s | 28.87s | +372.5% Grok 4.3 (High) is 372.5% slower |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $1.25 / $2.50 | |
| Input modalities | Text, Image | Text, Image |
Today's Pareto frontier
Against the frontier
- GPT-5.6 Luna (Medium) is off the frontier: at the same or lower cost, GPT-6 Luna (Medium) scores 29.90 for $31.2.
- Grok 4.3 (High) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Medium) scores 47.80 for $361.
GPT-5.6 Luna (Medium)Grok 4.3 (High)Today's Pareto frontierEvery other model
Matchup
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Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/gpt-5-6-luna-medium/grok-4-3 · Markdown: /api/v1/compare/gpt-5-6-luna-medium/grok-4-3?format=md · llms.txt · agent skill