GPT-5.6 Luna (Medium) vs Mercury 2.5
Which is better for the money: GPT-5.6 Luna (Medium) by OpenAI or Mercury 2.5 by Inception? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-24.
Clear winner
Verdict
Pick GPT-5.6 Luna (Medium)
Mercury 2.5 vs GPT-5.6 Luna (Medium): 50.8% less intelligence, 392.1% more cost to run the AA benchmark, and 24.6% faster end-to-end.
| Metric | GPT-5.6 Luna (Medium) | Mercury 2.5 | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 25.0 | 12.3 | −50.8% Mercury 2.5 is 50.8% less intelligent |
| Total AA cost (lower is better) | $44.32 | $218.11 | +392.1% Mercury 2.5 is 4.9× more expensive |
| End-to-end time (lower is better) | 5.82s | 4.39s | −24.6% Mercury 2.5 is 24.6% faster |
| Price per 1M tokens (in / out) | $0.20 / $1.20 | $0.25 / $0.75 | |
| Input modalities | Text, Image | Text |
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.
- Mercury 2.5 is off the frontier: at the same or lower cost, MiMo-V2.6-Pro scores 46.30 for $207.
GPT-5.6 Luna (Medium)Mercury 2.5Today'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/mercury-2-5 · Markdown: /api/v1/compare/gpt-5-6-luna-medium/mercury-2-5?format=md · llms.txt · agent skill