GPT-5.5 Instant (June 2026) vs GPT-5.6 Terra (Xhigh)
Which is better for the money: GPT-5.5 Instant (June 2026) by OpenAI or GPT-5.6 Terra (Xhigh) by OpenAI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-27.
Trade-off
Verdict
Depends on your budget
GPT-5.6 Terra (Xhigh) scores 12.0 points higher (38.0 vs 26.0) but costs 1.2× as much to run the benchmark ($1187 vs $987; both premium class). Pick GPT-5.6 Terra (Xhigh) when the extra intelligence is worth the premium, otherwise GPT-5.5 Instant (June 2026).
| Metric | GPT-5.5 Instant (June 2026) | GPT-5.6 Terra (Xhigh) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 26.0 | 38.0 | +46.2% GPT-5.6 Terra (Xhigh) is 46.2% more intelligent |
| Total AA cost (lower is better) | $986.85 | $1,186.77 | +20.3% GPT-5.6 Terra (Xhigh) is 20.3% more expensive |
| End-to-end time (lower is better) | 16.17s | 21.13s | +30.7% GPT-5.6 Terra (Xhigh) is 30.7% slower |
| Price per 1M tokens (in / out) | $5.00 / $30.0 | $2.00 / $12.0 | |
| Input modalities | Text, Image | Text, Image |
GPT-5.6 Terra (Xhigh) vs GPT-5.5 Instant (June 2026): 46.2% more intelligence, 20.3% more cost to run the AA benchmark, and 30.7% slower end-to-end.
Today's Pareto frontier
Against the frontier
- GPT-5.5 Instant (June 2026) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Xhigh) scores 51.00 for $662.
- 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.
GPT-5.5 Instant (June 2026)GPT-5.6 Terra (Xhigh)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-5-5-instant-06-26/gpt-5-6-terra-xhigh · Markdown: /api/v1/compare/gpt-5-5-instant-06-26/gpt-5-6-terra-xhigh?format=md · llms.txt · agent skill