GPT-5.6 Luna (Xhigh) vs GPT-6.1 Terra (Medium)
Which is better for the money: GPT-5.6 Luna (Xhigh) by OpenAI or GPT-6.1 Terra (Medium) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-27.
Clear winner
Verdict
Pick GPT-6.1 Terra (Medium)
GPT-6.1 Terra (Medium) vs GPT-5.6 Luna (Xhigh): 19.4% more intelligence, 2.3% less cost to run the AA benchmark, and 84.8% faster end-to-end.
| Metric | GPT-5.6 Luna (Xhigh) | GPT-6.1 Terra (Medium) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 34.6 | 41.3 | +19.4% GPT-6.1 Terra (Medium) is 19.4% more intelligent |
| Total AA cost (lower is better) | $179.33 | $175.20 | −2.3% GPT-6.1 Terra (Medium) is 2.3% cheaper |
| End-to-end time (lower is better) | 45.86s | 6.95s | −84.8% GPT-6.1 Terra (Medium) is 84.8% faster |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $1.00 / $5.00 | |
| Input modalities | Text, Image | Text, Image |
Today's Pareto frontier
Against the frontier
- GPT-5.6 Luna (Xhigh) is off the frontier: at the same or lower cost, GPT-6.1 Terra (Medium) scores 41.30 for $175.
- GPT-6.1 Terra (Medium) is on today's frontier: nothing is both smarter and cheaper.
GPT-5.6 Luna (Xhigh)GPT-6.1 Terra (Medium)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-xhigh/gpt-6-1-terra-medium · Markdown: /api/v1/compare/gpt-5-6-luna-xhigh/gpt-6-1-terra-medium?format=md · llms.txt · agent skill