GPT-5.5 (Xhigh) vs Mercury 2.5
Which is better for the money: GPT-5.5 (Xhigh) by OpenAI or Mercury 2.5 by Inception? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-25.
Trade-off
Verdict
Depends on your budget
GPT-5.5 (Xhigh) scores 26.1 points higher (38.4 vs 12.3) but costs 24× as much to run the benchmark ($5294 vs $218; flagship vs mid-range cost classes). They are not alternatives at one budget: pick GPT-5.5 (Xhigh) when you need intelligence above 12.3, and Mercury 2.5 when 12.3 is enough.
| Metric | GPT-5.5 (Xhigh) | Mercury 2.5 | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 38.4 | 12.3 | −68.0% Mercury 2.5 is 68.0% less intelligent |
| Total AA cost (lower is better) | $5,294.36 | $218.11 | −95.9% Mercury 2.5 is 95.9% cheaper |
| End-to-end time (lower is better) | 40.04s | 4.33s | −89.2% Mercury 2.5 is 89.2% faster |
| Price per 1M tokens (in / out) | $5.00 / $30.0 | $0.25 / $0.75 | |
| Input modalities | Text, Image | Text |
Mercury 2.5 vs GPT-5.5 (Xhigh): 68.0% less intelligence, 95.9% less cost to run the AA benchmark, and 89.2% faster end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.5 (Xhigh) is off the frontier: at the same or lower cost, Claude Opus 5.5 (Xhigh, Default Fallback) scores 56.00 for $4057.
- Mercury 2.5 is off the frontier: at the same or lower cost, MiMo-V2.6-Pro scores 46.30 for $207.
GPT-5.5 (Xhigh)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-5-5/mercury-2-5 · Markdown: /api/v1/compare/gpt-5-5/mercury-2-5?format=md · llms.txt · agent skill