GPT-5.6 Terra (Medium) vs Mercury 2
Which is better for the money: GPT-5.6 Terra (Medium) by OpenAI or Mercury 2 by Inception? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-24.
Trade-off
Verdict
Depends on your budget
GPT-5.6 Terra (Medium) scores 19.3 points higher (30.1 vs 10.8) but costs 4.3× as much to run the benchmark ($447 vs $105; both mid-range class). They are not alternatives at one budget: pick GPT-5.6 Terra (Medium) when you need intelligence above 10.8, and Mercury 2 when 10.8 is enough.
| Metric | GPT-5.6 Terra (Medium) | Mercury 2 | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 30.1 | 10.8 | −64.1% Mercury 2 is 64.1% less intelligent |
| Total AA cost (lower is better) | $446.53 | $104.94 | −76.5% Mercury 2 is 76.5% cheaper |
| End-to-end time (lower is better) | 5.85s | 8.08s | +38.1% Mercury 2 is 38.1% slower |
| Price per 1M tokens (in / out) | $2.00 / $12.0 | $0.25 / $0.75 | |
| Input modalities | Text, Image | Text |
Mercury 2 vs GPT-5.6 Terra (Medium): 64.1% less intelligence, 76.5% less cost to run the AA benchmark, and 38.1% slower end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.6 Terra (Medium) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Medium) scores 47.80 for $361.
- Mercury 2 is off the frontier: at the same or lower cost, Claude Haiku 5.5 (High) scores 37.80 for $94.1.
GPT-5.6 Terra (Medium)Mercury 2Today'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-terra-medium/mercury-2 · Markdown: /api/v1/compare/gpt-5-6-terra-medium/mercury-2?format=md · llms.txt · agent skill