Claude Fable 5.1 (Medium, Default Fallback) vs GLM-5.1 (Reasoning)
Which is better for the money: Claude Fable 5.1 (Medium, 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 2026-10-25.
Trade-off
Verdict
Depends on your budget
Claude Fable 5.1 (Medium, Default Fallb… scores 22.8 points higher (48.9 vs 26.1) but costs 2.7× as much to run the benchmark ($3983 vs $1487; flagship vs premium cost classes). Pick Claude Fable 5.1 (Medium, Default Fallb… when the extra intelligence is worth the premium, otherwise GLM-5.1 (Reasoning).
| Metric | Claude Fable 5.1 (Medium, Default Fallback) | GLM-5.1 (Reasoning) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 48.9 | 26.1 | −46.6% GLM-5.1 (Reasoning) is 46.6% less intelligent |
| Total AA cost (lower is better) | $3,983.28 | $1,486.78 | −62.7% GLM-5.1 (Reasoning) is 62.7% cheaper |
| End-to-end time (lower is better) | 14.35s | 64.38s | +348.6% GLM-5.1 (Reasoning) is 348.6% slower |
| Price per 1M tokens (in / out) | $10.0 / $50.0 | $1.28 / $4.07 | |
| Input modalities | Text, Image | Text |
GLM-5.1 (Reasoning) vs Claude Fable 5.1 (Medium, Default Fallback): 46.6% less intelligence, 62.7% less cost to run the AA benchmark, and 348.6% slower end-to-end.
Today's Pareto frontier
Against the frontier
- Claude Fable 5.1 (Medium, Default Fallback) is off the frontier: at the same or lower cost, Kimi K3.1 Pro scores 55.10 for $3117.
- 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 Fable 5.1 (Medium, 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-fable-5-1-medium/glm-5-1 · Markdown: /api/v1/compare/claude-fable-5-1-medium/glm-5-1?format=md · llms.txt · agent skill