Claude Opus 5.5 (Medium, Default Fallback) vs gpt-oss-20b (High)
Which is better for the money: Claude Opus 5.5 (Medium, Default Fallback) by Anthropic or gpt-oss-20b (High) by OpenAI? 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
Claude Opus 5.5 (Medium, Default Fallba… scores 42.2 points higher (51.2 vs 9.0) but costs 56× as much to run the benchmark ($1627 vs $28.8; premium vs budget cost classes). They are not alternatives at one budget: pick Claude Opus 5.5 (Medium, Default Fallba… when you need intelligence above 9.0, and gpt-oss-20b (High) when 9.0 is enough.
| Metric | Claude Opus 5.5 (Medium, Default Fallback) | gpt-oss-20b (High) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 51.2 | 9.0 | −82.4% gpt-oss-20b (High) is 82.4% less intelligent |
| Total AA cost (lower is better) | $1,626.81 | $28.81 | −98.2% gpt-oss-20b (High) is 98.2% cheaper |
| End-to-end time (lower is better) | 21.83s | 15.23s | −30.2% gpt-oss-20b (High) is 30.2% faster |
| Price per 1M tokens (in / out) | $4.00 / $20.0 | $0.05 / $0.22 | |
| Input modalities | Text, Image | Text |
gpt-oss-20b (High) vs Claude Opus 5.5 (Medium, Default Fallback): 82.4% less intelligence, 98.2% less cost to run the AA benchmark, and 30.2% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Opus 5.5 (Medium, Default Fallback) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
- gpt-oss-20b (High) is off the frontier: at the same or lower cost, GPT-6 Luna (Low) scores 21.50 for $10.6.
Claude Opus 5.5 (Medium, Default Fallback)gpt-oss-20b (High)Today'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/claude-opus-5-5-medium/gpt-oss-20b · Markdown: /api/v1/compare/claude-opus-5-5-medium/gpt-oss-20b?format=md · llms.txt · agent skill