GPT-5.6 Terra (Medium) vs Step 5 Preview
Which is better for the money: GPT-5.6 Terra (Medium) by OpenAI or Step 5 Preview by StepFun? 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
Step 5 Preview scores 13.6 points higher (43.7 vs 30.1) but costs 2.7× as much to run the benchmark ($1190 vs $447; premium vs mid-range cost classes). Pick Step 5 Preview when the extra intelligence is worth the premium, otherwise GPT-5.6 Terra (Medium).
| Metric | GPT-5.6 Terra (Medium) | Step 5 Preview | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 30.1 | 43.7 | +45.2% Step 5 Preview is 45.2% more intelligent |
| Total AA cost (lower is better) | $446.53 | $1,190.26 | +166.6% Step 5 Preview is 2.7× more expensive |
| End-to-end time (lower is better) | 5.85s | 12.08s | +106.5% Step 5 Preview is 106.5% slower |
| Price per 1M tokens (in / out) | $2.00 / $12.0 | $1.00 / $2.70 | |
| Input modalities | Text, Image | Text, Image |
Step 5 Preview vs GPT-5.6 Terra (Medium): 45.2% more intelligence, 166.6% more cost to run the AA benchmark, and 106.5% 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.
- Step 5 Preview is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
GPT-5.6 Terra (Medium)Step 5 PreviewToday's Pareto frontierOpen-weights 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/step-5 · Markdown: /api/v1/compare/gpt-5-6-terra-medium/step-5?format=md · llms.txt · agent skill