GLM-5.3-Flash vs GPT-6 Luna (Medium)
Which is better for the money: GLM-5.3-Flash by Z AI or GPT-6 Luna (Medium) by OpenAI? 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
GLM-5.3-Flash scores 11.9 points higher (41.8 vs 29.9) but costs 9.8× as much to run the benchmark ($306 vs $31.2; mid-range vs budget cost classes). They are not alternatives at one budget: pick GLM-5.3-Flash when you need intelligence above 29.9, and GPT-6 Luna (Medium) when 29.9 is enough.
| Metric | GLM-5.3-Flash | GPT-6 Luna (Medium) | Difference |
|---|---|---|---|
| Intelligence (higher is better) | 41.8 | 29.9 | −28.5% GPT-6 Luna (Medium) is 28.5% less intelligent |
| Total AA cost (lower is better) | $305.52 | $31.17 | −89.8% GPT-6 Luna (Medium) is 89.8% cheaper |
| End-to-end time (lower is better) | 39.33s | 8.25s | −79.0% GPT-6 Luna (Medium) is 79.0% faster |
| Price per 1M tokens (in / out) | $0.15 / $0.50 | $0.10 / $0.50 | |
| Input modalities | Text, Image | Text, Image |
GPT-6 Luna (Medium) vs GLM-5.3-Flash: 28.5% less intelligence, 89.8% less cost to run the AA benchmark, and 79.0% faster end-to-end.
Today's Pareto frontier
Against the frontier
- GLM-5.3-Flash is off the frontier: at the same or lower cost, MiMo-V2.6-Pro scores 46.30 for $207.
- GPT-6 Luna (Medium) is on today's frontier: nothing is both smarter and cheaper.
GLM-5.3-FlashGPT-6 Luna (Medium)Today's Pareto frontierOpen-weights frontierEvery other model
Matchup
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