GPT-5.6 Terra (Xhigh) vs Mercury 2
Which is better for the money: GPT-5.6 Terra (Xhigh) by OpenAI or Mercury 2 by Inception? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-26.
Trade-off
Verdict
Depends on your budget
GPT-5.6 Terra (Xhigh) scores 27.2 points higher (38.0 vs 10.8) but costs 11× as much to run the benchmark ($1187 vs $105; premium vs mid-range cost classes). They are not alternatives at one budget: pick GPT-5.6 Terra (Xhigh) when you need intelligence above 10.8, and Mercury 2 when 10.8 is enough.
| Metric | GPT-5.6 Terra (Xhigh) | Mercury 2 | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 38.0 | 10.8 | −71.6% Mercury 2 is 71.6% less intelligent |
| Total AA cost (lower is better) | $1,186.77 | $104.94 | −91.2% Mercury 2 is 91.2% cheaper |
| End-to-end time (lower is better) | 33.69s | 6.54s | −80.6% Mercury 2 is 80.6% faster |
| 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 (Xhigh): 71.6% less intelligence, 91.2% less cost to run the AA benchmark, and 80.6% faster end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.6 Terra (Xhigh) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
- 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 (Xhigh)Mercury 2Today's Pareto frontierEvery other model
Matchup
Compare something else
Agents:
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/gpt-5-6-terra-xhigh/mercury-2 · Markdown: /api/v1/compare/gpt-5-6-terra-xhigh/mercury-2?format=md · llms.txt · agent skill