Claude Opus 5.5 (Max, Default Fallback) vs GLM-5.1 (Reasoning)
Which is better for the money: Claude Opus 5.5 (Max, Default Fallback) by Anthropic or GLM-5.1 (Reasoning) by Z AI? Intelligence, total benchmark cost, and end-to-end time from Artificial Analysis & other sources, snapshot 2026-10-24.
Trade-off
Verdict
Depends on your budget
Claude Opus 5.5 (Max, Default Fallback) scores 31.5 points higher (57.6 vs 26.1) but costs 5.9× as much to run the benchmark ($8708 vs $1487; flagship vs premium cost classes). They are not alternatives at one budget: pick Claude Opus 5.5 (Max, Default Fallback) when you need intelligence above 26.1, and GLM-5.1 (Reasoning) when 26.1 is enough.
| Metric | Claude Opus 5.5 (Max, Default Fallback) | GLM-5.1 (Reasoning) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 57.6 | 26.1 | −54.7% GLM-5.1 (Reasoning) is 54.7% less intelligent |
| Total AA cost (lower is better) | $8,708.20 | $1,486.78 | −82.9% GLM-5.1 (Reasoning) is 82.9% cheaper |
| End-to-end time (lower is better) | 626.13s | 63.24s | −89.9% GLM-5.1 (Reasoning) is 89.9% faster |
| Price per 1M tokens (in / out) | $4.00 / $20.0 | $1.28 / $4.07 | |
| Input modalities | Text, Image | Text |
GLM-5.1 (Reasoning) vs Claude Opus 5.5 (Max, Default Fallback): 54.7% less intelligence, 82.9% less cost to run the AA benchmark, and 89.9% faster end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Opus 5.5 (Max, Default Fallback) is on today's frontier: nothing is both smarter and cheaper.
- GLM-5.1 (Reasoning) is off the frontier: at the same or lower cost, GPT-6.1 Sol (Max) scores 51.80 for $1082.
Claude Opus 5.5 (Max, Default Fallback)GLM-5.1 (Reasoning)Today's Pareto frontierOpen-weights frontierEvery other model
Matchup
Compare something else
Agents:
Accept: text/markdown or ?format=md returns this page as Markdown. JSON: /api/v1/compare/claude-opus-5-5/glm-5-1 · Markdown: /api/v1/compare/claude-opus-5-5/glm-5-1?format=md · llms.txt · agent skill